【整理】Web页面防止重复提交

    var isIe=(document.all)?true:false;
    //设置select的可见状态
    function setSelectState(state)
    {
      var objl=document.getElementsByTagName('select');
      for(var i=0;i<objl.length;i++){
        objl[i].style.visibility=state;
      }
    }
    function mousePosition(ev)
    {
      if(ev.pageX || ev.pageY){
        return {x:ev.pageX, y:ev.pageY};
      }
      return{
        x:ev.clientX + document.body.scrollLeft - document.body.clientLeft,y:ev.clientY + document.body.scrollTop - document.body.clientTop
      };
    }
    //弹出方法
    function showMessageBox(ev,wTitle,content,wWidth,isShowClose)
    {
      if( confirm('Confirm to Continue (确认此操作)?') )
      {
          var pos = mousePosition(ev);
          closeWindow();
          var bWidth=parseInt(document.documentElement.scrollWidth);
          var bHeight=parseInt(document.documentElement.scrollHeight);
          if(isIe){
            setSelectState('hidden');
          }
          var back=document.createElement("div");
          back.id="back";
          var styleStr="top:0px;left:0px;position:absolute;background:#666;"+bWidth+"px;height:"+bHeight+"px;";
          styleStr+=(isIe)?"filter:alpha(opacity=30);":"opacity:30;";
          back.style.cssText=styleStr;
          document.body.appendChild(back);
          showBackground(back,50);
          var mesW=document.createElement("div");
          mesW.id="mesWindow";
              
          var html = "<div style='border-bottom: #eee 1px solid;margin-left: 4px;padding: 3px;font-weight: bold;text-align: left;font-size: 12px;'>";
          html += "<table width='100%' height='100%'><tr><td>"+wTitle+"</td><td style='1px;'>";
          if( isShowClose == 1 )
          {
              html += "<input type='button' onclick='closeWindow();' title='Close(关闭窗口)' style='height: 15px; 28px;border: none;cursor: pointer;text-decoration: underline;background: #fff;' value='关闭' />";          
          }
          html += "</td></tr></table></div><div style='margin: 4px;font-size: 12px;padding:20px 0 20px 0;text-align:center' id='mesWindowContent'>"+content+"</div>";
          mesW.innerHTML= html ;
          var v_top=(document.body.clientHeight-mesW.clientHeight)/3;
          v_top+=document.documentElement.scrollTop;
          
          styleStr="border:#666 1px solid;background:#fff;top:"+v_top+"px;left:"+(document.body.clientWidth/2-mesW.clientWidth/2)+"px;position:absolute;600px;margin-left:-300px;left:50%;z-index:9999;";
          mesW.style.cssText = styleStr;           
           
          document.body.appendChild(mesW);      
          return true;
      }
      else
        return false;
    }
    //让背景渐渐变暗
    function showBackground(obj,endInt)
    {
      if(isIe){
        obj.filters.alpha.opacity+=5;
        if(obj.filters.alpha.opacity<endInt){
          setTimeout(function(){showBackground(obj,endInt)},1);
        }
      }else{
        var al=parseFloat(obj.style.opacity);al+=0.05;
        obj.style.opacity=al;
        if(al<(endInt/100)){
          setTimeout(function(){showBackground(obj,endInt)},1);
        }
      }
    }
    //关闭窗口
    function closeWindow()
    {
      if(document.getElementById('back')!=null){
        document.getElementById('back').parentNode.removeChild(document.getElementById('back'));
      }
      if(document.getElementById('mesWindow')!=null){
        document.getElementById('mesWindow').parentNode.removeChild(document.getElementById('mesWindow'));
      }
      if(isIe){
        setSelectState('');
      }
    }
    
    function showMessageBox_sample(ev)
    {
        return showMessageBox(ev,'友情提醒','Wating........(数据提交中，请耐心等待)',350,0);
    }

使用：btnSubmit.Attributes.Add("onclick", "return showMessageBox_sample(event);")