This is a great wrapper, but when posting to a asp.net web page, two additional post values need to be set:
ASIFormDataRequest *request = [ASIFormDataRequest requestWithURL:url];
//ADD THESE, BECAUSE ASP.NET is Expecting them for validation
//Even if they are empty you will be able to post the file
[request setPostValue:@"" forKey:@"__VIEWSTATE"];
[request setPostValue:@"" forKey:@"__EVENTVALIDATION"];
///
[request setFile:FIleName forKey:@"fileupload_control_Name"];
[request startSynchronous];