"Invalid Label" JSON error from $.POST method

Here is my Script

$(document).ready(function() {
$.post(
        "admin.php",
        { action: $(this).attr("action") },
        function(data) {
      开发者_运维百科      data = eval("(" + data + ")");
            alert(data);
            //alert(data.message);
        },"json"
    );
});

When I run this code, with the basic html page, it works. But when I use the same script in my actual page, it gives "invalid label" error.

My PHP code, to create the json string

$return = array("status"=>"true","message"=>"A new ".$this->title." has been added");
$json = json_encode($return);
return $json;

The error received at the the errors console at firebug

invalid label
[Break On This Error] {"status":"true","message":"A new CMS Type has been added"}
http://localhost/admin/admin.php?menu=2
Line 0

Help

Add this in your success method above your alert call

data = eval("(" + data + ")");

JS is interpreting your JSON incorrectly, adding the parenthesis will solve it. More info : http://www.bennadel.com/blog/99-JSON-Minor-But-VERY-Important-Detail-Creating-Syntax-Error-Invalid-Label.htm