禁止用F5键和禁止右键弹出菜单

			//禁止用F5键   
			function   document.onkeydown()   
			{   
			          if   (   event.keyCode==116)   
			          {   
			                  event.keyCode   =   0;   
			                  event.cancelBubble   =   true;   
			                  return   false;   
			          }   
			}   
			    
			//禁止右键弹出菜单   
			function   document.oncontextmenu()   
			{   
			      return   false;   
			}