Automate goal seek in two separate worksheets?

[tbl921]

Hi, I have a model that takes inputs to calculate the estimated cost of a new building. A second output is the estimated monthly payment to finance that cost. This output is based on one of two financing options, which a user selects from a drop down menu. The calculations for that monthly payment are on a distinct tab for each financing option. The calculation lays out, month by month, the loan principle, the monthly payment, and the end of month balance, for the entire term (one option's term is 30 years, the other is 40). I can of course use goal seek for the last end of month balance in each term to determine what the monthly payment would be. But on my forecast sheet, where the user can select inputs (e.g., how many people will live in the building and which financing option to use), the monthly payment is not correct until I manually go to that financing option's tab and run goal seek.

Is there a way to automate goal seek on each of those tabs, so that when the other model parameters change, the goal seek function runs automatically to determine the estimated monthly payment? I have tried some VBA codes pulled from forums, and also tried to record a macro for each tab, but am so far unsuccessful.

Thanks for any help!

 

[Worf]

Welcome to the Board

'ThisWorkbook module
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
Dim sh1 As Worksheet, sh2 As Worksheet
Set sh1 = Sheets("sheet1")
Set sh2 = Sheets("sheet2")
Select Case Sh.Name
    Case "Sheet1"
        If Not Intersect(Target, sh1.[c4:c13]) Is Nothing Then sh2.[c11].GoalSeek sh2.[e9], sh2.[c4]
    Case "Sheet2"
        If Not Intersect(Target, sh2.[c4:c13]) Is Nothing Then sh1.[c11].GoalSeek sh1.[e9], sh1.[c4]
End Select
End Sub