js实现右键弹出自定义菜单

//创建右键菜单
var epMenu={
  create:function(point,option){
    var menuNode=document.getElementById('epMenu');
    if(!menuNode){
      //没有菜单节点的时候创建一个
      menuNode=document.createElement("div");
      menuNode.setAttribute('class','epMenu');
      menuNode.setAttribute('id','epMenu');
    }else $(menuNode).html('');//清空里面的内容

    $(menuNode).css({left:point.left+'px',top:point.top+'px'});
    for(var x in option){
      var tempNode=document.createElement("a");
      $(tempNode).text(option[x]['name']).on('click',option[x].action);
      menuNode.appendChild(tempNode);
    }

    $("body").append(menuNode);
  },
  destory:function(){
    $(".epMenu").remove();
  }  
};

function sayhello(){
  alert("hellokity");
  epMenu.destory();
}

function hideSysMenu() {
  return false;
}

.epMenu{ width:120px; background:#f0f0f0; position:fixed; left:0; top:0; box-shadow:2px 2px 2px 2px #807878;}
.epMenu a{ display:block; height:25px; line-height:25px; padding-left:15px; border-top:1px solid #e0e0e0; border-bottom:1px solid #fff; font-family:微软雅黑; font-size:14px; cursor:default;}
.epMenu a:hover{ background:#fff;}

document.onmousedown = function(e){
    var menuNode=document.getElementById('epMenu');
    if(e.button===2){
      document.oncontextmenu = hideSysMenu;//屏蔽鼠标右键
      var evt = window.event || arguments[0];
      var rightedge = evt.clientX;
      var bottomedge = evt.clientY;
      epMenu.create({left:rightedge,top:bottomedge},[{name:'a1','action':sayhello},{name:'b2','action':sayhello},{name:'c3','action':sayhello},{name:'c4','action':sayhello}]);  
    }
//   epMenu.destory();
  }