使用NSURLRequest通过POST将键-值对传递给PHP脚本

I'm fairly new to objective-c, and am looking to pass a number of key-value pairs to a PHP script using POST. I'm using the following code but the data just doesn't seem to be getting posted through. I tried sending stuff through using NSData as well, but neither seem to be working.I'm fairly new to objective-c, and am looking t