For a GET request I\'ve tried this simple method:
NSString *urlAddress = @"http://example.com/";
NSURL *url = [NSURL URLWithString:urlAddress];
NSURLReq
Create POST URLRequest and use it to fill webView
NSURL *url = [NSURL URLWithString: @"http://your_url.com"];
NSString *body = [NSString stringWithFormat: @"arg1=%@&arg2=%@", @"val1",@"val2"];
NSMutableURLRequest *request = [[NSMutableURLRequest alloc]initWithURL: url];
[request setHTTPMethod: @"POST"];
[request setHTTPBody: [body dataUsingEncoding: NSUTF8StringEncoding]];
[webView loadRequest: request];