Stop to re enter data into db after refresh the browser
i used header (redirect to page ) but wen user press back button from browser and submit button is clicked data is entered again to db
Seems like its doing its job then. When you go back, don’t hit the submit button 
But if you really want us to help, then we need to see the code and a better explanation of what’s going on.
[php]<?php include_once('includes/header.php');?>
<?php include_once('../includes/register.class.php');?> <?php $std_array=array ("std_firstname","std_lastname","birth_day","birth_month","birth_year","cur_class","gender","father_firstname","father_lastname","gardian_relation","fbirth_day","fbirth_month","fbirth_year","father_occ","parent_nic","prev_inst","prev_class","prev_inst_percent","std_address1","std_address2","std_email","std_phone","country","std_city","std_mob"); if(isset($_POST['std_admission'])){ $register->stdAdmission($std_array); } ?>[/php][code] <div class="contents">
<div class="inner_nav">
<table>
<tr>
<td class="tab_nav">
<ul>
<li><a href="kidergarten.php">FEE STRUCTURE</a></li>
<li><a href="admission.php">ADMISSION FORM</a></li>
<li><a href="criteria.php">CRITERIA</a></li>
</ul>
</td>
</tr>
</table>
<div ><h1><img src="images/register_03.png" class="sign"><span>ADMISSION FORM</span></h1></div>
<div class="error">
<?php echo $register->GetError();
?>
</div>
<form action="" method="post" enctype="multipart/form-data">
<div class="outer_div">
<div class="heading_strip">STUDENT INFORMATION</div><!--Heading Strip-->
<div class="inner_left_div">
<div class="info">
<label class="lbl">Date</label>
<input name="form_date" type="text" readonly="true" class="txt_field" value="<?php echo date('d/m/y');?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">First Name</label>
<input name="std_firstname" type="text" class="txt_field" value="<?php if(isset($_POST['std_firstname']))echo $_POST['std_firstname'];?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">Last_Name </label>
<input name="std_lastname" type="text" class="txt_field" value="<?php if(isset($_POST['std_lastname'])) echo $_POST['std_lastname'];?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">Date Of Birth</label>
<select name="birth_month" class="formFields" id="birth_month">
<option value="<?php if(isset($_POST['birth_month'])) echo $_POST['birth_month']?>"></option>
<option value="01" selected="selected">January</option>
<option value="02">February</option>
<option value="03">March</option>
<option value="04">April</option>
<option value="05">May</option>
<option value="06">June</option>
<option value="07">July</option>
<option value="08">August</option>
<option value="09">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="birth_day" class="formFields" id="birth_day">
<option value="<?php if(isset($_POST['birth_day'])) echo $_POST['birth_day']?>"></option>
<option value="01" selected="selected">1</option>
</select>
<select name="birth_year" class="formFields" id="birth_year">
<option value="<?php if(isset($_POST['birth_year'])) echo $_POST['birth_year']?>"></option>
<option value="2020">2020</option>
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
<option value="2015">2015</option>
<option value="2014">2014</option>
<option value="2013">2013</option>
<option value="2012">2012</option>
<option value="2011" selected="selected">2011</option>
<option value="2010">2010</option>
<option value="2009">2009</option>
<option value="2008">2008</option>
</select>
</div><!--info-->
<div class="info">
<label class="lbl">Class</label>
<select name="cur_class" >
<option value="<?php if(isset($_POST['cur_class'])) echo $_POST['birth_month']?>"></option>
<option value="KG1" selected="selected">KG-1</option>
<option value="KG2">KG-2</option>
<option value="KG3">KG-3</option>
<option value="Nursery">Nursery</option>
<option value="Prep">Prep</option>
<option value="One">One</option>
<option value="Two">Two</option>
</select>
</div><!--info-->
<div class="info">
<label class="lbl">Gender </label>
<label><input name="gender" type="radio" value="female" checked="checked"/>Female</label>
<label><input name="gender" type="radio" value="male" />Male</label>
</div><!--info-->
</div><!-- inner_left_div-->
<div class="inner_right_div">
<div class="info">
<div class="std_pic"></div>
<input type="hidden" name="MAX_FILE_SIZE" value="1000000" />
<input name="std_pic" type="file"/>
<label class="lbl"></label><span class="php_link"><br/>2*2(inch)</span>
</div><!--info-->
</div><!--inner_right_div -->
<div class="heading_strip">GUARDIAN INFORMATION</div><!--Heading Strip-->
<div class="inner_left_div">
<div class="info">
<label class="lbl">First Name </label>
<input name="father_firstname" type="text" class="txt_field"value="<?php if(isset($_POST['father_firstname'])) echo $_POST['father_firstname'];?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">Last Name </label>
<input name="father_lastname" type="text" class="txt_field" value="<?php if(isset($_POST['father_lastname'])) echo $_POST['father_lastname'];?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">Date Of Birth</label>
<select name="fbirth_month" class="formFields" id="birth_month">
<option value="<?php if(isset($_POST['fbirth_month'])) echo $_POST['fbirth_month']?>"></option>
<option value="01" selected="selected">January</option>
<option value="02">February</option>
<option value="03">March</option>
<option value="04">April</option>
<option value="05">May</option>
<option value="06">June</option>
<option value="07">July</option>
<option value="08">August</option>
<option value="09">September</option>
<option value="10">October</option>
<option value="11">November</option>
<option value="12">December</option>
</select>
<select name="fbirth_day" class="formFields" id="birth_day">
<option value="<?php if(isset($_POST['fbirth_day'])) echo $_POST['fbirth_day']?>"></option>
<option value="01" selected="selected">1</option>
<option value="02">2</option>
<option value="03">3</option>
<option value="04">4</option>
<option value="05">5</option>
</select>
<select name="fbirth_year" class="formFields" id="birth_year">
<option value="<?php if(isset($_POST['fbirth_year'])) echo $_POST['fbirth_year']?>"></option>
<option value="2020">2020</option>
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
<option value="2015">2015</option>
<option value="2014">2014</option>
<option value="2013">2013</option>
<option value="2012">2012</option>
<option value="2011" selected="selected">2011</option>
<option value="2010">2010</option>
<option value="2009">2009</option>
<option value="2008">2008</option>
<option value="2007">2007</option>
<option value="2006">2006</option>
</select>
</div><!--info-->
</div><!-- inner_left_div-->
<div class="inner_right_div">
<div class="info">
<label class="lbl">Occupation</label>
<input name="father_occ" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['father_occ'])) echo $_POST['father_occ'];?>"/>
</div><!--info-->
<div class="info">
<label class="lbl">NIC</label>
<input name="parent_nic" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['parent_nic'])) echo $_POST['parent_nic'];?>"/>
<label class="lbl"> </label><span class="php_link">12345-1234567-1</span>
</div><!--info-->
<div class="info">
<label class="lbl">Relationship</label>
<input name="gardian_relation" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['gardian_relation'])) echo $_POST['gardian_relation'];?>" />
</div><!--info-->
</div><!--inner_right_div -->
<div class="heading_strip">PREVIOUS ACADAMIC DETAILS</div><!--Heading Strip-->
<div class="inner_left_div">
<div class="info">
<label class="lbl">Institute Name</label>
<input name="prev_inst" type="text" class="txt_field" value="<?php if(isset($_POST['prev_inst'])) echo $_POST['prev_inst'];?>" />
</div><!--info-->
<div class="info">
<label class="lbl">Year</label>
<select name="prev_year" class="op_style">
<option value="<?php if(isset($_POST['prev_year'])) echo $_POST['prev_year']?>"></option>
<option value="2020">2020</option>
<option value="2019">2019</option>
<option value="2018">2018</option>
<option value="2017">2017</option>
<option value="2016">2016</option>
<option value="2015">2015</option>
<option value="2014">2014</option>
<option value="2013">2013</option>
<option value="2012">2012</option>
<option value="2011" selected="selected">2011</option>
<option value="2010">2010</option>
<option value="2009">2009</option>
<option value="2008">2008</option>
</select>
</div><!--info-->
</div><!-- inner_left_div-->
<div class="inner_right_div">
<div class="info">
<label class="lbl">Class</label>
<select name="prev_class" >
<option value="<?php if(isset($_POST['prev_class'])) echo $_POST['prev_class']?>"></option>
<option value="KG1" selected="selected">KG-1</option>
<option value="KG2">KG-2</option>
<option value="KG3">KG-3</option>
<option value="Nursery">Nursery</option>
<option value="Prep">Prep</option>
<option value="One">One</option>
<option value="Two">Two</option>
<option value="Three">Three</option>
<option value="Four">Four</option>
<option value="Five">Five</option>
<option value="Six">Six</option>
<option value="Seven">Seven</option>
<option value="Eight">Eight</option>
</select>
</div><!--info-->
<div class="info">
<label class="lbl"> Result Percantage </label>
<input name="prev_inst_percent" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['prev_inst_percent'])) echo $_POST['prev_inst_percent'];?>" />
</div><!--info-->
</div><!--inner_right_div -->
<div class="heading_strip">CONTACT DETAILS</div><!--Heading Strip-->
<div class="inner_left_div">
<div class="info">
<label class="lbl">Address1</label>
<input name="std_address1" type="text" class="txt_field" value="<?php if(isset($_POST['std_address1']))echo $_POST['std_address1'];?>" />
</div><!--info-->
<div class="info">
<label class="lbl">Address2</label>
<input name="std_address2" type="text" class="txt_field" value="<?php if(isset($_POST['std_address2'])) echo $_POST['std_address2'];?>" />
</div><!--info-->
<div class="info">
<label class="lbl">Email</label>
<input name="std_email" type="text" class="txt_field" value="<?php if(isset($_POST['std_email'])) echo $_POST['std_email'];?>" />
<label class="lbl"> </label><span class="php_link">[email protected]</span>
</div><!--info-->
<div class="info">
<label class="lbl">Phone</label>
<input name="std_phone" type="text" class="txt_field" value="<?php if(isset($_POST['std_phone'])) echo $_POST['std_phone'];?>" />
<br/> <label class="lbl"> </label><span class="php_link">e.g. 1234567</span>
</div><!--info-->
</div><!-- inner_left_div-->
<div class="inner_right_div">
<div class="info">
<label class="lbl">Nationality </label>
<select name="country">
<option value="<?php if(isset($_POST['country'])) echo $_POST['country']?>"></option>
<option value="Abu Dhabi">Abu Dhabi</option>
<option value="Algeria">Algeria</option>
<option value="American Samoa">American Samoa</option>
<option value="Andorra">Andorra</option>
<option value="Angola">Angola</option>
<option value="Anguilla">Anguilla</option>
<option value="Antigua">Antigua</option>
<option value="Argentina">Argentina</option>
<option value="Armenia">Armenia</option>
<option value="Aruba">Aruba</option>
</select>
</div><!--info-->
<div class="info">
<label class="lbl">City</label>
<input name="std_city" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['std_city'])) echo $_POST['std_city'];?>" />
</div><!--info-->
<div class="info">
<label class="lbl">Mob.</label>
<input name="std_mob" type="text" class="txt_field" style="width:100;" value="<?php if(isset($_POST['std_mob'])) echo $_POST['std_mob'];?>"/>
<br/><label class="lbl"> </label><span class="php_link">e.g. 1234-1234567</span>
</div><!--info-->
</div><!--inner_right_div -->
<div class="heading_strip footer_strip">
<input name="std_admission" type="submit" value="SUBMIT" class="btn_style" />
</div><!--Heading Strip-->
</div><!--Outer Div-->
</form>
</div><!--form-div-->
</div>
<!--main Conetents area-->[/code]
[php]<?php include_once('includes/footer.php');?>[/php]
this is my HTML form file
[php]
public function stdAdmission($info){
$formval=$info;
if($this->isEmpty($formval)){
$this->error_message[]=“Please Fill Required Fields”;
}else{
$this->isStdFieldValid($formval);
$this->uploadPic();
if(!count($this->error_message)){
$this->saveStdToDB();
}
}
}
function saveStdToDB(){
$database = new MySQLDatabase();
$std_firstName= $_POST['std_firstname'];
$std_lastName=$_POST['std_lastname'];
$DOB_date=$_POST['birth_day'];
$DOB_mnth=$_POST['birth_month'];
$DOB_year=$_POST['birth_year'];
$class=$_POST['cur_class'];
$gender=$_POST['gender'];
$std_frfname=$_POST['father_firstname'];
$std_frlname=$_POST['father_lastname'];
$gard_relation=$_POST['gardian_relation'];
$fDOB_date=$_POST['fbirth_day'];
$fDOB_mnth=$_POST['fbirth_month'];
$fDOB_year=$_POST['fbirth_year'];
$f_occ=$_POST['father_occ'];
$f_NIC=$_POST['parent_nic'];
$prev_inst=$_POST['prev_inst'];
$prev_year=$_POST['prev_year'];
$prev_class=$_POST['prev_class'];
$rzlt_prcntge=$_POST['prev_inst_percent'];
$addr1=$_POST['std_address1'];
$addr2=$_POST['std_address2'];
$email=$_POST['std_email'];
$phone=$_POST['std_phone'];
$nat=$_POST['country'];
$city=$_POST['std_city'];
$mob=$_POST['std_mob'];
$insert_query = mysql_query('insert into student_tbl(
std_first_name,
std_last_name,
gender,
std_birth_month,
std_birth_day,
std_birth_year,
admission_for_class,
std_father_fname,
std_father_lname,
gard_relation,
father_dob_year,
father_dob_month,
father_dob_day,
std_father_nic,
std_father_occ,
prev_institute,
prev_class,
prev_class_year,
rzlt_prcntge,
address1,
address2,
std_email,
std_nationality,
std_city,
mob_number,
phone_number,
status
)
values
(
"' . $std_firstName . '",
"' . $std_lastName. '",
"' . $gender . '",
"' . $DOB_mnth . '",
"' . $DOB_date . '",
"' . $DOB_year . '",
"' . $class . '",
"' . $std_frfname . '",
"' . $std_frlname . '" ,
"' . $gard_relation . '" ,
"' . $fDOB_year . '",
"' . $fDOB_mnth . '" ,
"' . $fDOB_date . '" ,
"' . $f_NIC . '",
"' . $f_occ . '",
"' . $prev_inst . '",
"' . $prev_class . '",
"' . $prev_year . '",
"' . $rzlt_prcntge . '",
"' . $addr1 . '",
"' . $addr2 . '",
"' . $email . '",
"' . $nat . '",
"' . $city . '",
"' . $mob . '" ,
"' . $phone . '",0
)');
if($insert_query){
echo "234";
header('Location: thnks.php');
}else{die("Data cannot be inserted into DB ".mysql_error());}
}[/php]
i hope now it ll be help to help i Have cut out the drop down lists entries becoz code looks so lengthy to post