Question related to hidden sheet in excel VBA

Excel 

Hello Sir,

I have a two questions - 

>> 1st question - When i click in CANCEL two times, then it shows error message.

Like - 

when i click in DEBUG  button, then it will yellow line highlighted - 

 so ,what will i write in code, when i click in CANCEL so userform remove?

2nd question - How to add below code in UserForm_Initialize -

Please help...???

Here is the attached file.

Excel 

I have written this code to show userform.

Like - 

 If I close the form, Is there any code or adding a button so that it displays again? As the given code only gives us the option to display form when we open the workbook. Can you help me with adding a button or code to display user form instead of closing the whole workbook to get the it?

Please help...???

Here is the attached file.

Excel 

Change the UserForm_Initialize event procedure like this:

Private Sub UserForm_Initialize()
    Dim wsh As Worksheet
    For Each wsh In Worksheets
        If wsh.Visible = xlSheetVisible Then
            Me.cboWhichSheet.AddItem wsh.Name
        End If
    Next wsh
End Sub