What we are trying to do here is that we have a form with an id of upgrade_form. We also have a form called \'paypal_submit\' form. This form is blank. \'upgrade_form\' has
If you haven't already, you could try stepping through it using the built-in IE JavaScript debugger (built in since IE8, or downloadable pre IE8)?
Many people use firebug - because it's awesome :) but many people don't realise the hidden talent of the built in debugger in IE 8.
It's got the same fundemental features as any other script debugger, but here is a guide for the specific features if you haven't come across it before: