sure have
<<Costings.Style.SPQuantity*Costings.Style.SPinGBP,'#,##0.00'>>
see error attached
is it because it is a calculation???
Yes! it is.
<<Costings.Style.SPQuantity,'#,##0.00'>> works fine, but even enclosing the calculation in () doesn't resolve the error.
Woe is me! Do I really have to put this figure in the database????

