Crystal Reports Calculation Error

Hi All,

I have some issues with the following syntax:

if month({InvCredHead.DocDate}) = month({?DATE})

and year({InvCredHead.DocDate}) = year({?DATE})

//and {InvCredHead.SOURCE} = "CRED"

and {InvCredHead.ObjType} = "14"

and {InvCredHead.DocTotal} <> 0

then ({InvCredHead.DocTotal} - {InvCredHead.vatsum} - {InvCredHead.DiscSum}) * (-1)

ELSE

IF month({InvCredHead.DocDate}) = month({?DATE})

and year({InvCredHead.DocDate}) = year({?DATE})

//and {InvCredHead.SOURCE} = "INV"

and {InvCredHead.ObjType} = "13"

and {InvCredHead.DocTotal} <> 0

then ({InvCredHead.DocTotal} - {InvCredHead.vatsum} - {InvCredHead.DiscSum})

The INVCREDHEAD is a view that unions invoice and credit note headers.

If i exclude the  "*(-1)" from then ({InvCredHead.DocTotal} - {InvCredHead.vatsum} - {InvCredHead.DiscSum}) * (-1), the result returned is correct, only positive.

If i include the "*(-1), the result returned is zero

How can i get this to return the correct negative value?

Thanks in advance,

Regards,

Kiran