Set Query Criteria thru Function

Hi,
I'm setting a query criteria thru a function, i.e. V1="RED": SetCriteria(V1)
(setting global variable) and then I use in the Query Criteria another
function to get the global variable i.e. GetCriteria().
It works fine.
Now I want to set a criteria with multiple selections i.e.. V2="BLUE": V3=V1
& " or " & V2
and SetCriteria(V3) but it doesn't work.
I tried with adding (wrap around with) quotes to V1 and V2 but it doesn't
work.
I can make V3 looks like this ""RED" or "BLUE"". or "RED or BLUE"
Any suggestions?
Thanks