Crystal Reports Running Total Error

Message

     Trying to create a running total, here is my formual: 
@Total //forumual name
whileprintingrecords;
NumberVar Add; 
Add:= Add + {@Potential $}; 

It's adding up correctly on the Group footer, but when I put the @Total on the Report Footer its adding the last value on the group footer to the Total. 

Any ideas? What am I missing on the formual?

I have to use the above formual since crystal won't allow me to use the sum() function. 

Thanks!