Replacing error values "0" with "-"

Ok I know this has to be easy but im having a real tough time making the "0" value of a formula display as "-" instead. Im using Excel 2008 on a Mac fyi.

I have 2 tabs in my workbook,
the first is worksheet that i use to enter my data
the second tab has all the formulas and the end result of data im looking to print out.

on the second tab im using formulas like " =Data!B2 " (data being the name of my worksheet tab)
on the second tab I would like to display a "-" if there is no data present on the worksheet whereas what i have displaying now is "0"

Excel help said to wrap the formula with =IF(ISERROR(old_formula),"-",old_formula)
but to no avail it gives me another error saying that the formula contains an error
I attached a copy of the workbook template for reference

Help Please!

Hello,

the 0 returned by the formula if the referred cell is empty is not an error, therefore an ISError will not do much good.

You can format the cells with a custom number format that displays zero values as a - character.

Select the cells and format with custom number format

0;0;-;@

for plain numbers without decimals, or

#,##0.00;-#,##0.00;-;@

if you want to show thousand separator and two decimals
The syntax for custom number formats is

positive;negative;zero;text

cheers,