Speed Up This Macro

The attached spreadsheet is used to assign a job number to a contract. There are 2 macros - FindIt and OpenJobNumberForm. FindIt scans the list to see if the contract # being entered has already been entered. OpenJobNumberForm opens a form to allow the user to enter the date and the contract number. A formula in the spreadsheet assigns the next number in the sequence as the job number.

The issue is that the OpenJobNumberForm macro scans the entire spreadsheet before assigning a new job number. As the list gets longer, this process takes longer. Is there a way to speed this up (ie eliminate the need to scan the entire spreadsheet)?

Thanks in advance for any help.