joemckamey,
I created dynamic named ranges for your lists of senders and doctors. These grow and shrink automatically with the amount of data you have. The only restriction is that you may not have blanks in your list before the end of the data. Just keep adding names in column A.
Please consider whether you have enough functionality with the data validation dropdowns to meet your needs. I installed the autocomplete feature for the doctors (but not the senders). But were it my workbook, I wouldn't have done so unless you expect to have hundreds of doctors on the list.
Brad
