Losesing Values In The Next Function

I have a series of subs that pass variables but at one point the value gets lost.

I want to pass the value in variable "PremFundType0 " to the function "MonthlyProcessing" and have it assigned to "PremFundType". But the problem is that PremFundType loses its value in the next function.


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Public PremFundType As Integer
Public PremFundType0 As Integer
Public J As Integer
Public m As Integer

Sub Main()
PremFundType0 = 12
Call MonthlyProcessing(120, PremFundType0)
End Sub
Sub MonthlyProcessing(proj_yrs, PremFundType)

J = 1: m = 1
For J = 1 To (proj_yrs)
For m = 1 To 12
Call BOM_Charges..........