Disable Right Click In all browser's

<script language="javascript">

                   var message="This function is not allowed here.";
                   function clickIE4(){

                                 if (event.button==2){
                                 alert(message);
                                 return false;
                                 }
                   }

                   function clickNS4(e){
                                 if (document.layers||document.getElementById&&!document.all){
                                                if (e.which==2||e.which==3){
                                                          alert(message);
                                                          return false;
                                                }
                                        }
                   }

                   if (document.layers){
                                 document.captureEvents(Event.MOUSEDOWN);
                                 document.onmousedown=clickNS4;
                   }

                   else if (document.all&&!document.getElementById){
                                 document.onmousedown=clickIE4;
                   }

                   document.oncontextmenu=new Function("alert(message);return false;")

    </script>