Q: Can you change from answering calls by sliding to answering by tapping green or red?

I am wondering if you can change the settings of the iPhone 4S from using the feature of sliding to answer calls, to changing to having a red and green button, where you can just tap to answer or reject the call?

I know you can download hack software, but I wouldn't want to do this. Is there anything in the settings menu or is there anything that can be downloaded direct from Apple?