<script type="text/javascript">
function f1() {
  if(document.all) { return false; }
}
function f2(e) {
  if(document.layers || (document.getElementById && document.all)) {
    if(e.which==2 || e.which==3) { return false; }
  }
}
if(document.layers) {
  document.captureEvents(Event.MOUSEDOWN);
  document.onmousedown = f1;
}
else {
  document.onmouseup = f2;
  document.oncontextmenu = f1;
}
document.oncontextmenu = new function("return false");
</script>

http://www.apphp.com/index.php?snippet=javascript-blocking-right-click

This snippet code allows you to prevent the viewer from being able to right-click on your page. This can discourage the average user from borrow images or code from your site.

Blocking Right-Click in Browser with JavaScript

JavaScript