Here's a working example

Basically, you have to be careful with this sort of thing. If you take an extant javascript function, turn it to a string, and eval it, you might run into function redeclaration issues. If you are simply taking a function string from the server and you want to run it, you can do as I did on that jsfiddle:

Javascript

var myFunc = function test() {alert('test');};



$(document).ready(function() {

    var data = new Object();

    data.func = myFunc;

    var jsonVal = $.toJSON(data);

    var newObj = $.evalJSON(jsonVal);

    eval(newObj.func);

    test();

});​