Match two celles and fill the third cell with data from the fourth

Ok, so I'll give it a go.

In sheet 1 i have two columns:
AA filled with a number
BB that I want a formula to fill

In sheet 2 I have two colums:
CC filled with the same type of numbers as in AA
DD filled with info regarding the celles to the left (CC).

Now I would like BB to be filled with info from DD if AA matches CC. Is this possible?

Please se attached sample.

Help.xlsx

I get an error here, did you get it to work in the sample?

If you use NBVC second formula you should not get a Error.
In the Data in your column CC there is no 14,15,21 & 39.

=IFERROR(VLOOKUP(A2,'Ark2'!$A$2:$B$7,2,0),"Not Available")

Thanks alot, got it working now