Vlookup or Index

I have two columns of data (A & B). I need find all occurrences of "x" in column A, and then take the value in the corresponding column B. I will need to sum all the values found, to get a total.

I cannot sort the data based on column A or column B....so I'll need some sort of lookup reference to find each value and then sum them all up.

Anyone have any suggestions?

TIA

Try this

=SUMIF(a:a,"x",b:b)

Perfect!! Thanks a ton!