Invalid Reference to property Tab Index

I use the line code below to check as I go through my form. I code along with a function both on the fly checking up to current tab index and also total checking for submitting.  Any suggestion as to how correct this error?

Run-Time Error '2455':
"You entered an expression that has an invalid reference to the property Tab Index"

...on this line..

If mCtl.Properties("TabIndex") <= Screen.ActiveControl.Properties("TabIndex") Then
End If

...............from this function below:

Public Function chkCtl(ByRef mCtl As Control) As Boolean
  chkCtl = True
      If mCtl.Properties("TabIndex") <= Screen.ActiveControl.Properties("TabIndex") Then
  Select Case ExtractTag(mCtl.Tag, 2)
    Case "ne"
      If Len(Nz(mCtl.Value)) = 0 Then chkCtl = False
    Case "1ne"
      If Len(Screen.ActiveForm.txtPermitNo) > 0 And Len(Nz(mCtl.Value)) = 0 Then chkCtl = False
    Case ">0"
      If Not Nz(mCtl.Value) > 0 Then chkCtl = False
    Case "tf"
      If Nz(mCtl.Value, 99) <> 0 And Nz(mCtl.Value, 99) <> -1 Then chkCtl = False
  End Select
    End If
End Function