Calculating A Score From A Row Of Drop-down Values

I need help in calculating a score from a row of drop-down values.
I need to use the onChange to tally the score as the user moves across
9 categories (with drop-down selection of 1-9 or N/A) multiplied by a
weighted score. The final column for each employee would be the
calculated score. I know how to accomplish this with vbscript but I
need it to process on the screen so the user can see the calculated
score as they make selections. Also the code needs to execute as many
times as there are employee rows.(loop) I don't know how to do this
with Javascript

Here's the VBscript with the variables involved
Var S1 = Category 1 Weighted score
Var S2 = Category 2 Weighted score
Var S3 = Category 3 Weighted score
Var S4 = Category 4 Weighted score
Var S5 = Category 5 Weighted score
Var S6 = Category 6 Weighted score
Var S7 = Category 7 Weighted score
Var S8 = Category 8 Weighted score
Var S9 = Category 9 Weighted score
D5 = 0.92
Var Q11 = Category 1 drop-down Value(1-9) * S1
Var Q22 = Category 2 drop-down Value(1-9) * S2
Var Q33 = Category 3 drop-down Value(1-9) * S3
Var Q44 = Category 4 drop-down Value(1-9) * S4

If (Category 5 Value = "N/A") THEN
Q55 = ' '
Else
Var Q55 = Category 5 drop-down Value(1-9 or N/A) * S5
End If

Var Q66 = Category 6 drop-down Value(1-9) * S6
Var Q77 = Category 7 drop-down Value(1-9) * S7
Var Q88 = Category 8 drop-down Value(1-9) * S8
Var Q99 = Category 9 drop-down Value(1-9) * S9

If (Category 5 = "N/A") THEN
Var FinalScore = round(((Q11 + Q22 + Q33 + Q44 + Q66 + Q77 + Q88 + Q99)
/ D5),2)
else
Var FinalScore = round((Q11 + Q22 + Q33 + Q44 + Q55 + Q66 + Q77 + Q88 +
Q99),2)
end if

Can anyone help me converting this to javascript?