Private Sub Worksheet_Change(ByVal Target As Range)
If Target.Column <> 7 Then Exit Sub
If Target.Count > 1 Then Exit Sub
If Target = "Dispatch" Then
MsgBox "Hello"
End If
End Sub
It is counting the number of cells in Target - the selection. If it's greater than 1 it exits, because you only want the code to work on one cell at a time.