var txtInput;
        //下拉表当前选中项的索引 
        var currentIndex = -1; 
       
        //设置下拉表 相对于 文本输入框的位置
        function setPosition()
        {             
            var width = txtInput.offsetWidth;   
                     
           // var left = getLength("offsetLeft")+5-GetScrWidth();
           // var top = getLength("offsetTop")-GetTopHeight() + txtInput.offsetHeight;        
            var left = getLength("offsetLeft"); 
             var top = getLength("offsetTop")+ txtInput.offsetHeight;                  
            divContent.style.left = left + "px";
            divContent.style.top = top + "px"; 
            divContent.style.width = width + "px";
              
        } 
        
       //获取对应属性的对应的位置 
        function getLength(attr)
        {
            var offset = 0;
            var item = txtInput;
            while (item)
            {
                offset += item[attr];
                item = item.offsetParent;
            } 
            return offset; 
        } 

        //自动完成
        function autoComplete(txtname)
        {
       
            txtInput = document.getElementById(txtname);
             setPosition();
             
            //如果按下 向上, 向下 或 回车
            if (event.keyCode == 38 || event.keyCode == 40 || event.keyCode == 13)
            { 
                //选择当前项 
                selItemByKey();
            } 
            else //向服务器发送请求
            { 
                if (txtInput.value == "中文/拼音")
                {
                    txtInput.value="";
                }
                currentIndex = -1; 

                //开始请求
                requestObj = new ActiveXObject("Microsoft.XMLHTTP");
                requestObj.onreadystatechange = displayResult;
                requestObj.open("POST", "AJAX/AutoCity.aspx?" + new Date().toLocaleString(), true);
                requestObj.send(txtInput.value); 
                
                
           
           
            } 
        } 
        
        //显示结果 
        function displayResult()
        {
             if (requestObj.readyState == 4)
             {
                     showData();
                     divContent.style.display = "";
             } 
        } 
        
        //显示服务器返回的结果 ,并形成下拉表
        function showData()
        {
             //获取数据 
             var doc = new ActiveXObject("MSXML2.DOMDocument.3.0");
             doc.loadXML(requestObj.responseText);
             
             //显示数据的xslt 
             var docStyle = new ActiveXObject("MSXML2.FreeThreadedDOMDocument");
             docStyle.async = false; 
             docStyle.load("http://iticket.homsom.com/AJAX/list.xslt");
              
             var docTemplate = new ActiveXObject("MSXML2.XSLTemplate");
             docTemplate.stylesheet = docStyle;
             
             //通过xslt转换xml数据 
             var processor = docTemplate.createProcessor();
             processor.input = doc;
             processor.transform();
             var res = processor.output;
             
             //显示转后后的结果
             divContent.innerHTML = res; 
             
                try
                {                   
                    document.all("droNum").style.display="none";
                    document.all("droCabin").style.display="none";                    
                }
                catch (e)
                {}
             
        } 
        
        //通过键盘选择下拉项 
        function selItemByKey()
        {
            //下拉表 
            var tbl = document.getElementById("tblContent"); 
            if (!tbl)
            {
                return; 
            } 
            //下拉表的项数
            var maxRow = tbl.rows.length; 
            //向上 
            if (event.keyCode == 38 && currentIndex > 0)
            {
                 currentIndex--;
            } 
            //向下 
            else if (event.keyCode == 40 && currentIndex < maxRow-1)
            {
                 currentIndex++;
            }
            //回车 
            else if (event.keyCode == 13)
            {
                selValue();
                return;
            } 
            
            clearColor();
            
            var text = tbl.rows[currentIndex].innerText; 
            var sarray=new Array();
            sarray=text.split('-');
            txtInput.value = sarray[sarray.length-1]; 
            //设置当前项背景颜色为blue 标记选中 
            tbl.rows[currentIndex].style.backgroundColor = "#486cba"; 
        } 
        
        //清除下拉项的背景颜色 
        function clearColor()
        {
             var tbl = document.getElementById("tblContent");
             for (var i = 0; i < tbl.rows.length; i++)
             {
                    tbl.rows[i].style.backgroundColor = ""; 
             } 
        } 
        
        //选择下拉表中当前项的值 ,用于按回车或鼠标单击选中当前项的值
        function selValue()
        {
            if (event.keyCode != 13)
           { 
                var text = event.srcElement.innerText;
                var sarray=new Array();
                sarray=text.split('-');
                txtInput.value = sarray[sarray.length-1]; 
            } 
            initList(); 
           try
                {
                    document.all("droNum").style.display="block";
                    document.all("droCabin").style.display="block";                    
                }
                catch (e)
                {}
            
        } 
        
        //文本框失去焦点时 设置下拉表可见性 
        function setDisplay()
        {
            //获取当前活动td的表格 
            if (document.activeElement.tagName == "TD")
            {
                 var tbl = document.activeElement.parentElement.parentElement.parentElement; 
                //如果不是下拉表,则隐藏 下拉表 
                if (tbl.id != "tblContent")
                {
                    initList();
                }
                return;
            } 
            
            initList();
            
        } 
       
        function initList()
        {
            divContent.style.display='none'; 
            divContent.innerHTML = "";
            currentIndex = -1;
        }