Negative to Positive

[Okaria]

I just know I'm going to sound completely ignorant, but how does one go about converting a negative integer to a positive?

Also, is it possible to move a number-only string (like 15) to an integer variable? Example:

Dim Blah as Integer
Dim BlahString as String

BlahString = "15"
Blah = BlahString

Obviously, VB chokes on this with a type mismatch. Any wisdom you could share would be helpful, thanks very much.

- Evan Sims