Why when I use the code-

If ($Submit)
{
}

- in php do I get a undefined variable error?

Cas, March 2004

Or if you could do this:

if(isset($Submit)) {
// Code here
}

Easy Tiger, November 2010

This "error" is a Notice, rather than an actual error. You can change the php config on your server so that you don't get this Notice. This will make your code work.

In the php.ini file change the error_reporting config from...

error_reporting = E_ALL; display all errors, warnings and notices

to

error_reporting = E_COMPILE_ERROR|E_ERROR|E_CORE_ERROR

Lewis, March 2004