Empty Input field in VC SQL iview

Hello all,

I am using the VC to create a small iView to pull data from a MS-SQL DB. I have the iView built and things work for the most part. The issue I am having is I get the following error if any input field is left blank "Portal request failed (No value was assigned to parameter(@LastName))"

I have the stored procedure setup so that I if a null is passed in for any of the values it set the value to a '%'.

I am wonder if it is possible to either:

a) pass blank values

b) test if a value is blank before the submit and

change the value to a '%'.

Cheers,

D.