Is there a way to get a variable name as a string in Javascript? (like NSStringFromSelector in Cocoa)

I would like to do like this:

var myFirstName = 'John';
alert(variablesName(myFirstName) + ":" + myFirstName);

--> myFirstName:John

-- added

I'm trying to connect a browser and another program using JavaScript. I would like to send instance names from a browser to another program for callback method.