String.prototype.Trim = function() 
{ 
return this.replace(/(^\s*)|(\s*$)/g, ""); 
} 
function DrawImage(ImgD,w,h)
{
    var flag = false;
    var MyImage = new Image();
    MyImage.src = ImgD.src;

    if(MyImage.readyState != "complete")
    {
        return false; //确保图片完全加载
    }
    if(MyImage.width > 0 && MyImage.height > 0)
    {  
        flag = true;
        if(MyImage.width / MyImage.height >= w / h)
        {
            if(MyImage.width > w)
            {
                ImgD.width = w;
                ImgD.height = (MyImage.height * w) / MyImage.width;
            }
            else
            {
                ImgD.width = MyImage.width;
                ImgD.height = MyImage.height;
            }
        }
        else
        {
            if(MyImage.height > h)
            {
                ImgD.height = h;
                ImgD.width = (MyImage.width * h) / MyImage.height;
            }
            else
            {
                ImgD.width = MyImage.width;
                ImgD.height = MyImage.height;
            }
        }
    }
}
function isExc(form)
{
    var values = "";
    var j = 0;
     for (var i=0;i<form.elements.length;i++)    
     {
          var e = form.elements[i];
         
          if (e.checked == true && e.type == "checkbox")
           {  
                if(values.Trim().length == 0)
                {
                    values = e.id;
                }
                else
                {
                    values += "," + e.id
                }
                j++;
           } 
     }

  if(j == 0)
  {
        alert('请选择要对比的商品。');
  }
  else  
  {
    window.open("Compare.aspx?ids=" + values);
  }
  
}