how to get msgbox when cell value varies exel vba - vba

Question

I have a cell "A1" which varies the integer values from "1 to 150"
suppose if "A1"cell.Value ="1" then i should get msgbox containing its A1 value as "1".
and
if"A1"cell value = "2" then i should get msgbox containing its A1 value as "2"
similarly if A1 value is 3,4,5 and so on, then i should get respective cell value in msgbox
I wrote a code as seen below. but writing if code statement ranging from "1 to 150" is dificult task
can anybody minimise thise code adding variables to this.. thank you in advance
sub variable()
If Range("a1").Value = 1 Then
MsgBox Worksheets("Sheet1").Range("A1").Value
Else
If Range("a1").Value = 2 Then
MsgBox Worksheets("Sheet1").Range("A1").Value
Else
If Range("a1").Value = 3 Then
MsgBox Worksheets("Sheet1").Range("A1").Value
End If
End If
End If
End Sub

Answer 1

This is how to do rewrite the code with Select Case:
Sub MyVariable()
Select Case Range("A1").Value
Case 1 to 150:
MsgBox Range("A1")
Case Else:
'nothing
End Select
End Sub

Answer 2

I can suggest you to write this code :
Private Sub Worksheet_Change(ByVal Target As Range)
If (Target.Address = "$A$1") Then
If (IsNumeric(Target.Value)) Then
If (Target.Value >= 1 And Target.Value <= 150) Then
MsgBox Target.Value
End If
End If
End If
End Sub

Answer 3

If you want to get message each time you enter different value in cell A1 , then please use code below.
Private Sub Worksheet_Change(ByVal Target As Range)
Dim DivRg As Range
Set DivRg = Range("A1")
Set DivRg = Application.Intersect(Target, DivRg)
If DivRg Is Nothing Then Exit Sub
MsgBox Target
Set DivRg = Nothing
End Sub
Please note you should put this code in your Worksheet module, not regular module.