Submitting a trusted form to Sharepoint using custom code

[Hosehead17]

I have got some custom javascript code working for how I would like
this form to be submitted to a Sharepoint form library. However, I
would like to make this form a fully trusted form and every time I do
this it breaks the custom code that I have written, as far as I can
tell it stops at this line:

oXmlHttp.Open("HEAD", strUrl, false);

With strUrl defined as:

var strUrl = "http://aosvs1/RMA/RMA Tracking Form/Pending RMAs/"
+ fname.text + ".xml";

steve