Hi I need help on a formula if possible:

I have a data entry sheet which has "Date" and "Train Number" as labels.
There can be any number of entries for a day and the same train might appear
more than once in a day.

I need to calculate the number of trains per day without the duplicates

e.g.
DATE TRAIN No.
5/1/07 844
5/1/07 324
5/1/07 844
6/1/07 546
6/1/07 546
6/1/07 546
7/1/07 324
7/1/07 844
7/1/07 546

Should return a display of:
5/1/07 2
6/1/07 1
7/1/07 3

Many thanks for your help!

Marley