IF you want the textbox to return its name when you click in it use:

Private Sub Document_City_Enter()
MsgBox Me.Document_City.Name
End Sub

as previously provided, or

Private Sub Document_City_Enter()
MsgBox Me.ActiveConrol.Name
End Sub

as Paul provides, or

If you click a command button Document_City obviously no longer has the focus so:

Private Sub cmdTextBoxName_Enter()
MsgBox Me.ActiveControl.Name
End Sub

Naturally returns cmdTextBoxName, because cmdTextBoxName is now the active control.

__________________
Greg Maxey
Please visit my web site at http://www.gregmaxey.com/