I have 4 worksheet each with over 80 rows of information.

I want to lookup a code in one column, and if found I want the value from
the immediately adjacent column pulled out and added up eg:

code value
a 1.00
b 2.00
a 5.03
c 0.45
d 1.20
a 2.50

so that if I looked up "a" in the first column, it would add 1.00, 5.03 and
2.50 from the second column and spit out a total for me.

I want this to complete the same function on all 4 worksheets and get me the
total value from all worksheets for each code.

I've tried various function combinations of IF, VLOOKUP, SUM etc and can't
seem to get anything to return a result other than error. please help!