DateTime startTime;
Start()
{
 startTime = DateTime.Now;
}

timer_tick()
{
   //check in timer_tick or other method
   TimeSpan span = DateTime.Now - startTime;
   if (span.Minutes > 60)
   {
        Stop();
   }
}

<script type="text/javascript">

     function document.onkeydown()   
          {if(event.keyCode==116)   
                      {event.keyCode=0   
                          event.returnValue=false;   
                      }   
          }   
    
          document.oncontextmenu=function(){return   false}     

</script>