title: Allowing only one vote per person on a voting system
body: <p>I'm working on a little posting system so I can post posts on my site and people can like and dislike it.</p>
  
  <p>It looks like this:</p>
  
  <p><img src="https://i.stack.imgur.com/uX9tA.png" alt="the voting system"></p>
  
  <p>At the moment you can upvote and downvote as many times as you would like. I know how to make the images not clickable with JavaScript but I also need a way to do this in PHP because someone could just make the buttons clickable again with fireBug or the Chrome Console.</p>
  
  <p>This is probable the first thing i'm actually making in PHP so i'm still a beginner. Thanks for any suggestions.</p>