[Javascript] Testing for "undefined" (undefined vs. null)

[Craig Michael Nathan]

I have a wacky problem in that using 
	top.frames
sometimes returns "undefined".

I'm curious how I can test for "undefined".

I tried:
	if (top.frames == null) return;
	
But have since learned that null != undefined

Any ideas?

	Much appreciated,

			-Craig


*****************************
Craig Michael Nathan
Chief Technology Officer
MEconomy, Inc.
cnathan at MEconomy.com

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