The jquery Ajax request returns Boolean and object, traversing the object

HTML code:

<Tr>
<TD> <FMT: Message key = "ttesbill. cusomerid"/> </TD>
<TD> <select name = "cusomerid" class = "cusomerid" style = "width: 165px">
<Option> --- Select --- </option>
<C: foreach items = "$ {banklist}" Var = "banklist">
<Option value = "$ {banklist. cusomerid}" >$ {banklist. customername} |$ {banklist. cardno} </option>
</C: foreach>
</SELECT>
</Tr>

Jquery code:

$ ("Select [name = 'cusomerid']"). Change (function (){

VaR cusomerid = $ ("option: Selected", this). Val (); // get the drop-down box Value

$. Ajax ({
Type: "Post", // use post to submit a request
URL: "$ {CTX}/ttesbillcontroller. do? Method = getcusomer ", // submit the URL
Data: "cusomerid =" + cusomerid, // submit Parameters
Success: function (data, status) {// process the returned Function
If (status = "success") {// confirm the return value
For (var p in data) // cyclically traverses an object
$ ("Input [name =" + P + "]"). Val (data [p]); // fill in the HTML text box
}
},
Error: function (){
Alert ("an error occurred... your operation is incorrect ");
}
});
});

Java code:

Public modelandview getcusomer (httpservletrequest request,
Httpservletresponse response ){
String cusomerid = request. getparameter ("cusomerid ");
Tbankcustomer tbank = tbankcustomerservice. gettbankcustomerbyid (cusomerid );
Renderjson (response, jsonutil. tostring (tbank, jsonutil. collection_filter ));
// Return object, no need to convert
Return NULL;
}

Returns a Boolean value in JSON format.

Renderjson (response, tojson ("success", flag ));