Help related to like dislike button

Question

Hi I am making a forum , i need help regarding making like dislike button as we see in this site to every reply.

 

Is there any chance that i can get some code or and idea about how to design those like dislike mechanism. I have tried this but didnt got success. so 

please guide me on this.  This will be a gr8 help from the experts.

Thanks in Advance....