Using variables in data reports

hi, i am using access as my database and i have a question. i want to create a report that will show all the products from my table where the userfield is equal to the current user.
Now, the userid is held in a global variable but when i use it in my sql builder in the data report it doesnt work, but if i write the number in my sql e.g 344mm it works.
anybody help please?
thanks

my guess is that for a post not having a reply then it should be very difficult to answer. anyways if anybody comes up with a solution let me know.