OK, I have 3 columns. I need to delete column 2/3 if column2 does not have a match in column1.
If column2 DOES have a match in column1 I need it moved in the file to line up with its matching
column1 line so that I end up with something like the second example. Blanks where column1 
contains entries that do not exist in column2. It is important that column3 stay with it's 
original column2 and matching column1 entry.

I'm doing by hand/eyeball in OpenOffice Calc now but with 1700+ lines in column1 and 5000+ in 
column2/3 it's gonna take a while.

Ideas??



a1		a1	x1
a2		ax	x2
a3		ay	x3
a4		a3	x4
a5		a4	x5
a6		aq	x6
a7		az	x7
a16		aw	x8
		a6	x9
		ad	x10
		af	x11
		a7	x12
		ag	x13

-----------------------

a1		a1	x1
a2			
a3		a3	x4
a4			
a5			
a6		a6	x9
a7		a7	x12
a16