how do i get the right url to be returned in www?

I am using the www class and the wwwform class to upload files to a remote server. I have a php script on the server end that should be accessed by the javascript on the client side. I have a url that i pass in the www constructor which is supposed to access the php script on the server but i believe that its not getting to the php script because it returns the html page instead. what would be a reason for this to happen and what ways can i get it to work right?