How to implement php form submiting

[system]

i dont know php

<?php echo file_get_contents("http://s2.freesmsapi.com/messages/send?skey=a35cd7asssced6992c78453198210e7e55&message=".urlencode('msg here')."&recipient=user number here"); ?>

the above code is my php API given bt SMS provider … if i paste this code in my contact.php it is auto matially sending sms , but i need to send sms when

user enter some message in a text box and click submit then it should send sms

i dont have much knowledge of php please show some code

[richei]

You’re not checking to see if the submit button was clicked.
[php]if(isset($_POST[‘submit’])) { // name of submit button
echo file_get_contents(“http://s2.freesmsapi.com/messages/send?skey=a35cd7asssced6992c78453198210e7e55&message=”.urlencode(‘msg here’)."&recipient=user number here");
}[/php]