SQL Reporting :: Tune This Custom Code?

I have developed this code .It is giving sumpoistive ,sumnegative correct .But count of positives and count of negatives it is not showing value...It is not showing error but not giving result..it is giving 0 as count for the coun_positive n for negative aslo..

Please tune my logic...

Public pos_sum AS INTEGER =0
Public neg_sum AS INTEGER=0
Public pos_coun AS INTEGER
Public neg_coun AS INTEGER
FUNCTION SUMFUNCTION(ByVal Field AS INTEGER) AS INTEGER
if Field>0 then
pos_sum=pos_sum+Field
return Field
End IF
IF Field<0 then
neg_sum=neg_sum+Field
return Field
End IF
End FUNCTION
FUNCTION COUNTFUNTION(ByVal Field AS INTEGER) AS INTEGER
if Field>0 then
pos_coun=pos_coun+1
return pos_coun
END IF
IF Field<0 then
neg_coun=neg_coun+1
return neg_coun
End IF
END FUNCTION
Function SumPositive() AS INTEGER
return pos_sum
End FUNCTION
Function SumNegative() AS INTEGER
return (-neg_sum)
End FUNCTION
Function couPositive() AS INTEGER
return pos_coun
End FUNCTION
Function couNegitive() AS INTEGER
return neg_coun
End FUNCTION