In Python one can get a dictionary of all local and global variables in the current scope with the built-in functions locals() and globals(). Is t
locals()
globals()
Well, I don't think that there is something like that in js. You can always use eval instead of locals(). Like this:
eval(s+"()");
You just have to know that actually function foo exists.
Edit:
Don't use eval:) Use:
var functionName="myFunctionName"; window[functionName]();