I need to be able to have this macro running on a worksheet automatically. It would be to allow pasting text only into ALL cells on the worksheet.

How would I do this?
Sub Macro1()
'
' Macro1 Macro
'    Columns("A:A").Select
    ActiveSheet.PasteSpecial Format:="Text", Link:=False, DisplayAsIcon:= _
        False
End Sub
Note: I recorded this macro however, I need to change the columns realistically to say columns A through P and always be active on the spreadsheet.

I attempted to place it on the worksheet as 
Private Sub Worksheet_Activate()

End Sub

Private Sub Worksheet_SelectionChange(ByVal Target As Range)
Sub Macro1()
'
' Macro1 Macro
'

'
    Columns("A:A").Select
    ActiveSheet.PasteSpecial Format:="Text", Link:=False, DisplayAsIcon:= _
        False
End Sub
End Sub
No luck could someone clean this up for me? thanks...