there are 3 different types of comboboxes.

Which are you using
1) List option in Data, Validation
2) Combobox from the control toolbox toolbar
3) DropDown box from the forms toolbar


For 1) and 3) you might look at Debra Dalgleish's site:

Dependent lists - data validation
http://www.contextures.com/xlDataVal02.html


Datavalidation - top
http://www.contextures.com/xlDataVal01.html

for number 2) use the change event of the first combobox to set the
rowsource or otherwise load the second combobox.

--
Regards,
Tom Ogilvy


"scrabree" wrote in message
...
I want the row source for combobox # 2 to be conditional
to the selection the user makes in combo box #1. The row
source for combo box 2 will either be sheet 1 A1:A10 or
Sheet 1 B1:B10 depending on the selection in combo box 1.