Dear all,

I'm trying to implement a little look up routine in Excel (not in VBA) and can't quite seem to crack it.

Essentially, I have rows of data showing min and max values in separate columns. Starting with the first row, I want to look down at each row and flag with an "x" those rows which have min and max values (i.e. ranges) which don't overlap with any other rows. The columns are sorted from min to max.

For instance given the following data:

0 10
10 30
10 35
10 37
20 40
40 45
40 47
50 60

The function I need would start with an x in row 1 and find all subsequent non-overlapping ranges, hence:

0 10 x
10 30 x
10 35
10 37
20 40
40 45 x
40 47
50 60 x

The first range goes up to 10, so the function would then look for the next row which begins with 10 or more, which is the range in row 2, which is 10 to 30, etc..

Any help would be gratefully appreciated, any questions just ask