Enumerate your javascript object object's methods a.k.a. javascript intellisense
In the system that I am currently maintaining, everything is a mess. You just won't know how to find something or where to find something unless you go down deep into their code. Hell!
So while debugging a javascript portion and after hours of searching I still couldn't find the method in an object for which I am looking... I thought a way of evaluating the object's method would be possible in javascript. How do you do this? It's just a few lines of code! I dunno if this will work on other browsers but it did in IE7.
for (var property in yourobject)
{
alert("Property: " + voucher[property] + "\r\n");
}