Excel 2007 : Lock part of formula in cell

[ritkar2]

I am trying to lock part of a formula in a cell so it wont change when I drag and copy cell down. Example: B5=21.3%.......B13=$2500.00......C13 shows "=Sum(B5*B13)"-so cell shows result as $532.50.......I want to lock B5 of the formula so I can drag and copy the formula down to multiple cells without changing the formula from B5 to B6, B7, etc....can anyone help me? I tried the $ before the B5, but it still changes the cell.

[NBVC]

You have to make it absolute with $ in front of the row number...

e.g

=Sum(B$5*B13)

[ritkar2]

Thank you so much...it worked..I apparently was putting the $ in the wrong spot. Can you help me with one more issue. When I copy the formula down the rows, it puts a "$-" in each cell since there is no amounts to calculate yet. Is there a way to keep the cells blank until I put a dollar amount in B14 or B15, etc. Then the formulated result will show up C14 or C15 etc.

[NBVC]

Maybe...

=IF(OR(B14="",C14=""),"",the SUM formula above)