Submit Data after checking all validation

[system]

Hi All,
I am new in php and stuck in a problem which mention as under:
I have a form with the name of Sale Entry which contains the fields;

No Sale (Checkbox)
Distributor Name (Text)
Dealer List (Text)
Serial No (Numbers)

Now I wish to validate if

1. “No sale box is checked and Serial Number is empty”, No Sale should be insert in the table without any checking.
2. "No Sale box is not checking and Serial number is not empty, Serial No should be checked in Dealer sale table whether it is exists in the table or not. if exists “Duplicate Entry not allowed” Msg should display.
3. if Serial Number is not against correct Distributor, “Invalid Serial No” Msg should be display and
   Data should enter in the Dealer sale table after passing above criteria so that data hygine can be maintain. please help if anybody know the solution.
   Thanks,
   Best Rgds,
   Sukhdev Singh

[grwebugy]

You haven’t given us much information to know what you know about PHP.

You can start with:
http://php.net/manual/en/tutorial.forms.php
http://www.w3schools.com/php/php_form_validation.asp

And then tell us what you are having trouble with. A sample of the code you are editing might help too.