If, when your .asp scripts error, you are receiving the default '500 Error' message you need to change a setting in Internet Explorer to allow you to see the full detailed error message :

Open up Internet explorer,

Choose 'Tools' from the top menu,

Choose 'Internet Options' from the drop down menu,

Click on the 'Advanced' tab,

Scroll down until you see a tick box for 'Show friendly HTTP error messages',

Make sure this box is UNticked.

You will now get the full, detailed error message from your browser when one of your scripts fails. Knowing the error will help you troubleshoot it accordingly.