javascript/webservices call

I am building a few different suitelets, and one of them requires the list of item options of a particular item. The only way I can see of getting this is by using a nlapiRequestUrl call from within the form, similar in concept to the StrikeIron example, which I have working. my problem is that when I run the call I get an http: 500 error, and cannot seem to get the header argument in the script to appear in the response. So either the port request is wrong, or i am missing something.....

Here is the code:


function call_login()