点击td转换成input，失去焦点时发送修改数据

<script type="text/javascript">
var req;
var gID;
var bak;//备份一份
function changeToInput(id){
var oNP=document.getElementById(id);
var value = oNP.value;
oNP.outerHTML="<input type='text' id='"+id+"'value='"+value+"' size='20' onblur='change(this.id)'>"
document.getElementById(id).focus();
bak = value;
}
function change(id){
var oNP=document.getElementById(id);
var value = oNP.value;
if(value==bak){//如果数据没有更改，则还原到span
oNP.outerHTML="<span id='"+id+"' value='"+value+"' onclick='changeToInput(this.id)'>"+value+"</span>";
return;
}
gID=id;

init();
var url="manage.portal?action=updatePayout&id="+id+"&type="+value;
url=encodeURI(url);
url=encodeURI(url);//写一个不行。如果写一个就是？？？？号。写2个，则输出 %df%a4这种.

req.open("GET",url,true);
req.onreadystatechange=callback;
req.send(null);
}
function init(){
if(window.XMLHttpRequest){
req=new XMLHttpRequest();
}else if(window.ActiveXObject){
req=new ActiveXObject("Micrsoft.XMLHTTP");
}
}
function callback(){
if(req.readyState==4){
if(req.status==200){
var oNP=document.getElementById(gID);
var value=oNP.value;
oNP.outerHTML="<span id='"+gID+"' value='"+value+"' onclick='changeToInput(this.id)'>"+value+"</span>";
}
}
}
</script>

//html部分
<td>
<div align="center">
<span id=<bean:write name="item" property="id"/>  onclick="changeToInput(this.id)" value=<bean:write name="item" property="type"/>>
<bean:write name="item" property="type"/>
</span>
</div>
</td>

if("updatePayout".equals(form.getAction())){
String id=request.getParameter("id");
String type=request.getParameter("type");
try {
id=java.net.URLDecoder.decode(id,"UTF-8");
type=java.net.URLDecoder.decode(type,"UTF-8");//chinese <-->English
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//chinese <-->English
Payouttype payouttype=this.getManageService().getPayouttype(id);
payouttype.setType(type);
this.getManageService().update(payouttype);
System.out.println("------------更新成功------------");
initPayoutTypeList(mapping,form,request,response);
return mapping.findForward("payoutManage");
}