GoTo is not defined - in VBA - excel

Question

When I on the step F8 click. then say it Goto is not defined. I try to make a inputbox with a messagebox that me the answer give. And I try also to make code when the values not correct is. See, you where I make a mistake in my VBA code:
Sub TwoNumbersinputbox()
Dim bytAnswer1 As String
Dim bytAntwer2 As String
Dim Range As Byte
Dim strNumber1 As String
Dim strNumber2 As String
[C3] = "Number1"
[C4] = "Number2"
Start1:
strNumber1 = InputBox("Give number one?", "Invoer", 5, 567, 567)
If IsNumeric(strNumber1) Then
MsgBox "This must be Number1", vbCritical, _
"Number1 input"
GoTo strNumber1
Else: [B2] = strNumber1
End If
If Not IsNumeric(strNumber1) Then
MsgBox "there is error.", vbCritical, "Number2 input"
bytAnwer1 = MsgBox("Start Again?", vbYesNo)
If bytAnwer1 = vbYes Then GoTo Start
End If
Start2:
strGetal2 = InputBox("Give Number2?", "Input", 5, 567, 567)
If IsNumeric(strNumber2) Then
MsgBox "This must be Number2 ", vbCritical, _
"Number2 input"
GoTo strNumber2
Else: [B3] = strNumber2
End If
If Not IsNumeric(strGetal2) Then
MsgBox "Is there an error.", vbCritical, "Number2 input"
bytAnswer2 = MsgBox("Start Again?", vbYesNo)
If bytAnswer2 = vbYes Then GoTo Start
End If
End Sub

Answer 1

First thing first - never use GOTO. Only in error handling (On Error statement (VBA)).
Second - if you need to use it, a mark is needed. E.g., if it is GoTo somewhere, then in the code it should be defined like this - somewhere:.
Sub DontUseGoTo()
Dim i As Long
i = 0
somewhere:
i = i + 1
Debug.Print i
If i < 10 Then
GoTo somewhere
End If
End Sub