Can anyone tell me why this search won't work

Can anyone tell me why this search won't work?
When run I get an error message saying OPERATION IS NOT SUPPORTED FOR THIS TYPE OF OBJECT.

It is searchg for a mooring number in a harbour management project I'm working on. The form tht it is on has information from two different tables displayed on it in text boxes. It has two data controls.

I would be grateful for any help

Cheers!

Code:Private Sub cmdFind_Click()
prompt$ = "Enter the full Mooring Number e.g 001 "

SearchStr$ = InputBox(prompt$, "Mooring Search")
Data2.Recordset.Index = "Mooring Number"
Data2.Recordset.Seek "=", SearchStr$
If Data2.Recordset.NoMatch Then
Data2.Recordset.MoveFirst
End If
End Sub

Try changing

Data2.Recordset.Index = "Mooring Number"

to

Data2.Recordset.Index = "[Mooring Number]"