Many many thanks,
But the table I will use is something like that
http://www17.brinkster.com/vakyuz/Kitap1.htm
And I need to know for which lines there is a conflict (Çakışma). Such that
one teacher can not take a lesson more than one.
If the way you know is programming via Visual Basic, please include more
details, because I am very novice in programing visual basic in Excel. Many
thanks again

"jchen":

I will Use:
Dim oldAddress= acitvecell.address
Find(cell value, By Row)
if no error, and no change row then
msgbox "duplicate found"
Range(oldAddress).select

Somthing like that.