I have a form where a user check 1-4 options. these options tell me what they need for tools. "If checkbox 1 then bring (a,b,c)" So the problem is when someone check more then one box some of the tools overlap (e.g. Option 1 requires "a,b,c" Option 2 requires "a,d,e") So when they populate the list box how do I remove duplicates?