[SOLVED] Conditional formatting, alternate row colour to promote easy reading of long list

Hi there

I have a long list of invoice lines. It is multiple columns. First two columns are Invoice # and Invoice line. Neither the invoice # nor the invoice line # is necessarily consecutive in the list. The list may look like:
Invoice # Invoice Line # InvDate Qty etc etc
12345 1 10/10/2010 1000
12345 3 10/10/2010 46
17010 2 17/10/2010 100
10001 4 09/10/2010 9
10001 5 09/10/2010
10001 7 09/10/2010

I would like to highlight the rows to promote easier reading/skimming, with alternate (say) blue and white on the entire row. In the above example this would mean the 2 lines for Invoice 12345 would be white, the single line for Inv 17010 would be blue, the three lines for Inv 10001 would be white etc etc. Banded highlighting, breaking on invoice #, alternating between two colours.

Is this possible?

TIA

Ralph in Auckland