Help with validation list using vlookup or index match

[SP01]

I have sheet with two columns, say A and B.

I would like to enter text into A and have B show a validation list of values based on what has been entered into A. In another sheet there is a simple list of the values A could have and the associated values B should have. eg:

Sheet 1
A B (list)
Apple Juice Carton
Glass
Jug

Sheet 2
A B
Apple Juice Carton
Apple Juice Glass
Apple Juice Jug
Pear Juice Glass
Pear Juice Jug

I cant use column A in Sheet 1 as a list as I would like this populated from another source

Any assistance would be greatly appreciated
Thanks!