Hello
Thanks stworthy, but...
I can not bring it to work

This is what I have:
Under button, I call (onClick) ChangeMember() function, and here is complete function:
function changeMember()
{
current = $('#members_tree').treegrid('getSelected').id;
if (current){
$.get('/json/member.json', function(data){
$('#dlg').dialog('open').dialog('setTitle','Edit Member');
$('#form_member').form('load', data);
var zip = $('#zip').val();
alert(zip);
});
}
}
I'm not sure that above is correct, so please tell me what's wrong?
this is JSON file:
{
"firstname": "daniela",
"lastname": "something",
"zip": 2224
}
Thanks!