Listbox Sum Procedure

[mrlnmarce]

Hey everyone,

Need some help with this. I am working on a budget allocation
worksheet.
I have a listbox that has Month/Year in it. When this is selected, I
need the cost of a particular project (in the same row) to be assigned
to a total for that month. This value needs to be able to be updated
from other worksheets in the same workbook. Any ideas?

Thanks in advance.