Errors

[smoothasice at geocities.com]

Ok I have been using python and I have noticed that the errors aren't
truly helpful.. I don't know if I just didn't learn this properly but I
dont' know why this generates an error:

for word in All_Words:
	z = 0
	while z < len(word):
		if z == 0:
			tally = tally + alpha.index(word[z])
		else:
			tally = tally + (alpha.index(word[z]) * 26)

It gives me this: NameError: tally
and I don't know why......

THanks,
Anton