Variable Dosnt Exist

[Medic873]

I am trying to make a program pull some basic data from a sevral websites...

But my issues is there are 4 variables it pulls

But two of the websites dont have all for variables they just pull 2 of them..

This isnt a problem on my end but what I would like is for my program to say IF Variable no declaired then $Hello = 0

So here is kindof a example code.

$Hello =  1

if $Hello = 1 then $What = 1
if $Hello = 2 then $What = 2
if $Hello2 DOSNT EXISTS then $What = 0

Anyone know how I can do this easily I have been sweeping the help file all day and havnt found anything

thank you very much

[PsaltyDS]

If Not IsDeclared("Hello2") Then $What = 0

Edit: Good point from jchd below, if you have to do this, you're doing it wrong.

Edited July 6, 2011 by PsaltyDS

[jchd]

Design issue: you rule on your own variables, so you should know which ones you declared.