Close all the other workbooks except current workbook based on a vbYes and vbNo answer

[Pookiemeister]

Sub isAnyWorkbookOpen()        
    Dim wb As Workbook
    Dim wbs As Workbooks
    Dim msg As String
    Dim Result
    
    msg = "The following workbook(s) must be closed before continuing:" & Chr(10) & "Do you want to close?" & Chr(10) & Chr(10)
    
    Set wbs = Application.Workbooks
    
    For Each wb In wbs
        If wb.Name <> ThisWorkbook.Name Then msg = msg & wb.Name & Chr(10)
    Next wb
    
    If Len(msg) > 0 Then
        Result = MsgBox(msg, 52, "Workbooks Open")
    Else
         [COLOR=#008000]'Close MessageBox[/COLOR]
    End If
    If Result = vbYes Then
        wb.Close
    Else
        
    End If
End Sub

The problem with code above is that I get a "Runtime error 91: Object variable or with block variable not set" and when I click debug it highlights "wb.Close" I just want to close all the workbooks except the current one. Also if the user clicks "No" then I need the messagebox to close. I already tried

Cancel = True

but I get a "Compile error: Variable not defined" with the word Cancel highlighted in blue. However, on this issue I shouldn't have to do anything because when I click the No button it automatically closes the msgbox anyways. Am I wrong on that observation?

Thank you

 

[JoeMo]

Assuming the code is in the workbook that is the only workbook you want open (except a hidden Personal workbook if you have one), you don't really need a message box.

Sub CloseAllButThisOne()
Dim wb As Workbook
For Each wb In Application.Workbooks
    If wb.Name <> "PERSONAL.XLSB" And wb.Name <> ThisWorkbook.Name Then
        wb.Close
    End If
Next wb
End Sub