Validate if values associated with the same part number are in descending order

Hello,
I tried posting this question in General Excel, hoping that I could solve this with a formula--but I didn't have any luck. I will go an give my sincere thanks to the chap who tried to help me. I think I may need a VBA script, and I have only created simple VBA programs in the past.

I have a data dump from another external database. It looks something like this:

Part_ID Value
101 1
101 2
101 3
102 2
102 1

I have to verify that the values are in descending order for each part number and flag the rows that are not. So in the example above row 5 would be flagged.

I have a dump of about 1000 rows of data.

Any assistance would be greatly appreciated!
Cheers!
Forbes

Perhaps try, assuming data in columns A and B starting at row 1
C2=(A2&B2)*1
D3 =C3>C2
copy fomulas and paste down to the end of your data