Query by form problems

[spurs100]

Hello,

I have a query that takes its parameters from a form, however i am having trouble with one of the fields. I am tring to limit the records by using expressions i.e less than (<) then a number in the form field but i keep getting an error message saying the expression is too complex, if i put this expression in the criteria box in the Query by Grid field it works fine.

hope i have expalined my problem well!!!!!!!!!!

Please help!!!!

thanks in advance