Sending to PHP file on server using Post in iOS application

Question

I am sending data to the php file on the server using post using following code

     NSString *post =[[NSString alloc] initWithFormat:@"UserName=%@&UserPassword=%@",appDelegate.userName,appDelegate.userPassword];

     NSLog(@"post is %@",post);


     NSURL *url=[NSURL URLWithString:@"http://ec2-50-94-162-129.compute-1.amazonaws.com/usercredential.php?"];

     NSLog(@"URL is %@",url);



    NSData *postData = [post dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];



    NSString *postLength = [NSString stringWithFormat:@"%d", [postData length]];

    NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init] ;
    [request setURL:url];
    [request setHTTPMethod:@"POST"];
    [request setValue:postLength forHTTPHeaderField:@"Content-Length"];
    [request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
    [request setHTTPBody:postData];


    NSError *error;
    NSURLResponse *response;
    NSData *urlData=[NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

    NSString *data=[[NSString alloc]initWithData:urlData encoding:NSUTF8StringEncoding];


    NSLog(@"%@",data);

    data = [data stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
    NSLog(@"%@",data);

This shows login Failed if I access directly file from browser and provide userNAme in address then it works fine it does not work from iPhone app