Custom code sum

Morning guys,

I've got a quick question on generating report totals at the end of a report.

At the moment I've got totals at the bottom of each group, these are generated using custom code as I needed a way to sum the results of a look up. The totals at the bottom of each group work fine but I can't seem to find a way to allow me to generate report totals at the end as the custom code just seems to sum what is within the final group.

My code is

Dim public nettotal as Double 
Public Function Getvalue (ByVal subtotal AS Double) AS Double 
nettotal =nettotal + subtotal 
return subtotal 
End Function 

Public Function Totalvalue() 
return nettotal 
End Function