My brain hurts today and I basically don't want to do this...

Can anyone whip up a reg. exp to match a valid (US) currency value
in the range $0.00 to $9999.99, defined as:

1. Optional leading dollar-sign
2. 0-4 digits
3. Followed by an optional decimal
4. Followed by 1 or 2 optional digits

Mucho Thanks