Please could someone fill in the lines commented out, or tell me what I need to use for it to work please?

Private Sub BtnEditSupplier_Click()
Dim InputBoxResult As String
Dim rstSupId As DAO.Recordset

InputBoxResult = InputBox("Please enter the ID of the Supplier you wish to edit", "SupplierId")
MsgBox InputBoxResult

Set rstSupId = db.OpenRecordset("TblSupplier", dbOpenDynaset)

If Not (rstSupId <> Null) Then ' If there is something in the record
' Add an if statement in to check the supplier ID is in the table
DoCmd.OpenForm "FrmSupplier", acNormal, "SupplierID =" & InputBoxResult
' Else
'MsgBox "There is no supplier in this table with that ID, please try again or contact the IT team if you are unsure of the ID of a supplier."
End If
End If
End Sub

The supplierID is the first Field in the table.