Hàm SLN

Dim Fmt, InitCost, SalvageVal
Dim MonthLife, LifeTime, PDepr
Const YEARMONTHS = 12    ' Number of months in a year.
Fmt = "###,##0.00"    ' Define money format.
InitCost = InputBox("What's the initial cost " & _
           "of the asset?")
SalvageVal = InputBox("What's the asset's value " & _
             "at the end of its useful life?")
MonthLife = InputBox("What's the asset's useful " & _
            "life in months?")
' Ensure period is >= 1 year.
Do While MonthLife < YEARMONTHS 
    MsgBox "Asset life must be a year or more."
    MonthLife = InputBox("What's the asset's " & _
                "useful life in months?")
Loop
' Convert months to years.
LifeTime = MonthLife / YEARMONTHS 
If LifeTime <> Int(MonthLife / YEARMONTHS) Then
    ' Round up to nearest year.
    LifeTime = Int(LifeTime + 1)    
End If
PDepr = SLN(InitCost, SalvageVal, LifeTime)
MsgBox "The depreciation is " & _
       Format(PDepr, Fmt) & " per year."