Setting as Default = "all"  on Add "All" to Combo # Name error or does not return to Null on Click of Option

Option Compare Database
 
 
Private Sub cmbSearchbyName_AfterUpdate()
    gTP = Me.cmbSearchbyName.Value
    Select Case gTP
        Case "All"
            strSQL = "Select * from qryEmergentWk where Tech_grp_person "
        Case Else
            strSQL = "Select * from qryEmergentWk where Tech_grp_person = " & Chr(39) & gTP & Chr(39) & ""
    End Select
        Forms![frmEmergentWkFilter]![sub1].Form.RecordSource = strSQL
End Sub
 
Private Sub cmdClose_Click()
    DoCmd.OpenForm "Switchboard", acNormal, , , acFormEdit, acDialog
End Sub
 
Private Sub Form_Current()
    Me.cmbSearchbyName.RowSource = _
        "SELECT A.Name FROM (Select 'All' as Name From Personnel Union SELECT Name FROM Personnel) AS A ORDER BY A.Name"
    Me.cmbSearchbyName.DefaultValue = "All"
 
End Sub
 
Private Sub Form_Open(Cancel As Integer)
    For Each frm In Forms
        If frm.Name <> Me.Name Then DoCmd.Close acForm, frm.Name
    Next frm
End Sub
 
Private Sub frmOption_AfterUpdate()
    gTP = Me.cmbSearchbyName.Value
    Select Case frmOption
       Case 1
            Select Case gTP
                Case "All"
                    strSQL = "Select * from qryEmergentWk where Tech_grp_person"
                Case Else
                    strSQL = "Select * from qryEmergentWk where Tech_grp_person = " & Chr(39) & gTP & Chr(39) & ""
            End Select
        Case 2
            Select Case gTP
                Case "All"
                    strSQL = "Select * from qryEmergentWk where Tech_grp_person and Status <> 'Completed'"
                Case Else
                    strSQL = "Select * from qryEmergentWk where Tech_grp_person = " & Chr(39) & gTP & Chr(39) & " and Status <> 'Completed'"
            End Select
            Forms![frmEmergentWkFilter]![sub1].Form.RecordSource = strSQL
   End Select
 
End Sub