Preventing refresh

[Anon]

Does any one have any good suggestions on preventing users from refreshing pages,

***************problem*************

I have scripts that run SQL statements, after the script is run the user is redirected to anther page, however if the user clicks the back button on the browser and refreshes the page the script is recompiled and errors are displayed i.e. PRIMARY KEY VIOLATIONS etc.....

What is a good solution to prevent this type of activity?

[[deleted]]

You can create very complex methods using sessions or cookies, or you could simply check the data and see if the value you are trying to insert already exists.

[Anon]

Set a session variable on successful completion and only do the database work if that variable is not set

if ( ! $db_work_done ) {
//Do database work
$db_work_done = true;
session_register( "db_work_done" );
header ( "Location: somepage.php" );
}

You will need to initalize $db_work_done to false somewhere before this page.