Question : Multiple Criteria in Query

I need to have a query that filters multiple inputs from a user on a form. There are three "combo boxes" on the form but they all may not be filled. How can I format the criteria for three different fields to filter the data if an input is chosen, but not to filter if it is left blank??

What I have right now is:

IIf(IsNull([Forms]![frmCatSrch]![Combo11]),"",[Forms]![frmCatSrch]![Combo11])

but the query is still empty when no input is selected form "combo 11". Is there a way to omit a criteria if the combo box is nul??

Thanks

Answer : Multiple Criteria in Query

What you are proposing is not as straightforward as you may think.  Most motherboards designed for 65nm processors don't work with 45nm processors unless they explicitly have a BIOS upgrade that enables the support - I thought my MSI P6N would support the Wolfdales, since it had 1333 FSB support, but that was not the case.  The LGA775 socket is not enough to guarantee this, and I had to buy a new board to run an E8400.