//liujj added 删除请与本人联系
 //取得xmlHttpRequest
        function getXMLRequester( )
	    {    
		    var xmlhttp_request = false;    
		    try
		    {    
		        if( window.XMLHttpRequest )
			    {            
				    xmlhttp_request = new XMLHttpRequest();  
				          
				    if (xmlhttp_request.overrideMimeType)
				    {                
					    xmlhttp_request.overrideMimeType('text/xml');            
				    }       
			    }      
			    else if( window.ActiveXObject )
                {           
                    for( var i = 5; i; i-- )
                    {               
					    try
					    {                   
						    if( i == 2 )
						    {
							    xmlhttp_request = new ActiveXObject( "Microsoft.XMLHTTP" );                       
						    }
						    else
						    {
							    xmlhttp_request = new ActiveXObject( "Msxml2.XMLHTTP." + i + ".0" );	
							    xmlhttp_request.setRequestHeader("Content-Type","text/xml");xmlhttp_request.setRequestHeader("Content-Type","gb2312");                
						    }
						    break;
					    }               
					    catch(e)
					    {   
                            xmlhttp_request = false;              
                        }          
                     }       
			    }
		    }
		    catch(e)
		    {        
			    xmlhttp_request = false;   
		    }    
		    return xmlhttp_request ;
	    }
	    
	    function doHttpRequest(url,params,method,contentType,CallBack)
	    {
	        // 加随机数防止缓存
		    if (url.indexOf("?") > 0)
		    {
		        url += "&randnum=" + Math.random();
		    }
		    else
		    {
		        url += "?randnum=" + Math.random();
		    }
    		
		    var xmlHttp=getXMLRequester();
		    if (!method)
		    {
			    method="GET";
		    }
		    if (!contentType && method=="POST")
		    {
			    contentType='application/x-www-form-urlencoded';
		    }
		    if (xmlHttp)
		    {
			    xmlHttp.onreadystatechange=function()
			    {
//				    alert(xmlHttp.status);
				    if (xmlHttp.readyState == 4) 
				    {// 收到完整的服务器响应            
					    if (xmlHttp.status == 200) 
					    {//HTTP服务器响应的值OK
					    if(CallBack)
						    CallBack(xmlHttp);
					    }
				    }
				    
			    }
			    
			    if (contentType)
			    {
				    xmlHttp.setRequestHeader('Content-Type',contentType);
			    }
			    
			    xmlHttp.open(method,url,false);
    			
			    xmlHttp.send(params);
		    }
		    else
		    {
		        throw new Error("不能创建请求对象！")
		    }
	    }