兼容浏览器 阻止冒泡事件

    <script>
    
        var div = document.getElementsByTagName("div")
      
        div[0].onclick=function(){
            var ev = window.event||ev
                alert(3)
                

        }
        div[1].onclick=function(){
            var ev = window.event||ev
            if( ev.cancelBubble=true){
            ev.cancelBubble=true  
          }
          else{
            ev.stopPropagation() 
          }
          alert(2)
        }
        div[2].onclick=function(){
            var ev = window.event||ev
            if( ev.cancelBubble=true){
            ev.cancelBubble=true  
          }
          else{
            ev.stopPropagation() 
          }
      
                alert(1)
        }
    
    
    
    
    
    </script>