I have created a resource distribution table that allows me to select
multiple resources from a pull down menu. I then can distribute my resource
hours by month and fiscal year on another worksheet within the workbook.

In order to prevent my hours from being zero'd out when I select a new
resource type, I examine the cell in which I now have data in. If I have data
in the cell and the resource type does not match the resource name in column
"A" I do not zero the data. Data is zero'd on the distribution tool manually
by selecting a clear button macro I created.

Example of formula: "=IF($F6=0,0,IF($A6='Support Dist Hrs.
tool'!$N$3,IF($G$2='Support Dist Hrs. tool'!$I$10,$F6*('Support Dist Hrs.
tool'!$J$10)),$G6))"

This creates a circular reference that I need to eliminate as other users
will be using this tool.