Turning a string into a variable

[PRAVEEN KANKANALA <praveen@...>]

Let's say:

x = "foo"

But now I want to see if foo itself is an assigned variable (i.e. foo ~= nil  --- but since I don't know the sting contained in x, I can't do this directly) 

So is there someway to find out if a string (held in a variable) is also a variable, and if so, is it possible to get at the contents of that variable?


Praveen