I am having the WORST time trying to get PayPal Express Checkout to work. I'm using Go Daddy and they are of no help.

I was getting a blank screen at first when trying to test my site live by making a purchase and checking out using Paypal Express but now I keep getting the 500 - Internal Server Error. I looked at my error log and found the following:

[01-Dec-2009 21:27:20] PHP Warning: include(includes/languages/english/html_includes/define_main_page.php) [<a href='function.include'>function.include</a>]: failed to open stream: No such file or directory in D:\Hosting\5194009\html\zencart\includes\templates\template_default\templates\tp l_index_categories.php on line 39

[01-Dec-2009 21:27:20] PHP Warning: include() [<a href='function.include'>function.include</a>]: Failed opening 'includes/languages/english/html_includes/define_main_page.php' for inclusion (include_path='.;C:\php5\pear') in D:\Hosting\5194009\html\zencart\includes\templates\template_default\templates\tp l_index_categories.php on line 39

I made sure that the define_main_page.php file was on the server (at first it didn't look like it was) but I am still getting the same error. I was thinking that I needed to add a command or something to line 39 on the tpl_index)categories.php file but I don't know enough to know if I were doing it correctly so I haven't.

I could REALLY use some help, guidance, something. I need to get this site up and running correctly ASAP. PLEASE HELP!!