html实现网站全局按钮点击后置灰，不允许连续点击

 <script>
     document.addEventListener("mouseup", upHandler, true);
     function upHandler(e){
         var target=undefined;
         //元素类型即BUTTON
         if(e.target.tagName=='BUTTON'||(e.target.type!=undefined&&e.target.type.toUpperCase()=="BUTTON"))
         {
             target=e.target;
         }//样式按钮
         else if($(e.target).hasClass('btn')) {
             target=e.target;
             if(e.target.parentElement.tagName=='A')
             {
                 //<a><span class="btn">按钮<span></a>
                 target=e.target.parentElement;
             }
         }

         if(target!=undefined)
         {
             ///事件执行先后顺序，如果直接在mouseup里面置灰，会屏蔽掉原有的点onclick击事件
             // mousedown>mouseup>onclick>click>on()
             $(target).click(function(){
                 //a标签disabled属性无效
                 if(target.tagName=='A')
                 {
                     $(target).addClass('a-disabled');
                     setTimeout(function(){
                         $(target).removeClass('a-disabled');
                     },2000);
                 }
                 else{
                     target.setAttribute('disabled','disabled');
                     setTimeout(function(){
                         target.removeAttribute('disabled');
                     },2000);
                 }

             });
         }
     };
 </script>

 <style>
     .a-disabled
     {
         opacity: 0.6;
         cursor: default;
         pointer-events: none;
     }
 </style>