How do I Count Unique Values With Conditions?

[Scrambler307]

I need to count unique values using conditions. I believe I need an aray formula. Can anyone help me? Here is my data. It has blanks and text in the columns. I need to count "Job type" by unique "Job Number".
The answer I am looking for should look like this.

ANSWER
A = 3
P = 4
J = 1
V = 1
E = 1

RAW DATA
A B
Job_Type Job_Number
A 2011-0161
A 2011-0107
P 1991-341A
P 1991-341A

P 1991-341A

J 2011-588A

P 2007-0001

P 2011-0118
A 2011-0157
A 2011-0157
P 1991-341A
P 2011-0008

P 2011-0118
E 2011-0001
V 2011-0001

 

[T. Valko]

I re-wrote some of th formula to make it work across several worksheets within the workbook and I had no problems. I processed a ton of data, Thanks. Lastly, and I dont know if this is possible, can anyone explain the science behind the aray formula so I can write my own? Is there a trick to writing these?
Thanks a bunch!

See this for info on array formulas:

http://www.cpearson.com/Excel/ArrayFormulas.aspx