Flash CS3 AS2 - Convert String to Function name

programming flash
1

I am using AS 2 in Flash CS3 and XML. I have the function named in the XML file which I would like to be called via a rotating banner. However I can’t seem to convert the string (read via the XML file) to convert to the function name.

a trace reveals that the correct string is being called:
_parent._parent._parent.loadFunction.

urls[count] is the array that stores the function name.

Here is the script:
button.onRelease = function(){

    this[urls[count]]();

trace(urls[count]);

}

I have tried as many variations as I can including:
this[urls[count]]; (with the () as part of the XML string)
this[“urls”+count];
this._parent._parent._parenturls[count];

When the correct string is placed within the onRelease function, it works as expected. But using the “this[ ]” to convert the string to a function name is not working for me.
What am I missing??

Any help would be greatly, greatly appreciated.

Thanks in advance.