//动态修改选中或取消
	  var xmlHttp5;
	  var ids5 ;
	  function createXMLHttpRequest5() 
      {
        if(window.XMLHttpRequest)
		{
				xmlHttp5 = new XMLHttpRequest();
				xmlHttp5.onload = handleStateChange5;
				xmlHttp5.onerror = handleStateChange5;
		}
		else if(window.ActiveXObject)
		{
				try
				{
				  xmlHttp5 = new ActiveXObject("Msxml2.XMLHTTP"); 
				}
				catch(e)
				{
				  try
				  {
				      xmlHttp5 = new ActiveXObject("Microsoft.XMLHTTP");
				  }
				  catch(e)
				  {
				  }                        
				}
				xmlHttp5.onreadystatechange = handleStateChange5;
		}
      }	
	  function changeState(id)
	  {
				ids5 = id;
		        createXMLHttpRequest5(); 
		        var urlString = "savecom.mb";
		        var dataString = "id="+id;
		        xmlHttp5.onreadystatechange=handleStateChange5;
			    xmlHttp5.open("POST",urlString,true);
			    xmlHttp5.setRequestHeader("Content-Type","application/x-www-form-urlencoded;");
			    xmlHttp5.send(dataString);
	  }
	  
	function handleStateChange5()
	{
	   if(xmlHttp5.readyState==4)
	   {
	      if(xmlHttp5.status==200)
	      {    
	           if(xmlHttp5.responseText=="1"){
	             alert("对比数量不能超过4个");
	             document.getElementById(ids5).checked=false;
	           }
	           
               
	      }
	   }
	}