I don't see how you can have it both ways; i.e. you cannot pick from a child combo if there's no value in a parent because the values in a child combo are filtered by a choice in the parent. If you could, there would be no point as the child would have to show a complete list regardless of whether or not a parent value was chosen. Each subsequent combo row source needs a WHERE clause that restricts its records to those where there is a matching value in the field that the parent combo gets its list from. If you research this you'll find tons of examples from which to pick. Assuming cmbPOD is the control name, its value is text and this is in vba code, perhaps something like
Code:
"SELECT DISTINCT FRT_Table.[POD Name] FROM FRT_Table WHERE FRT_Table.[POL Name] = '" & Me.cmbPOD & "' ORDER BY FRT_Table.[POD Name]"
If not code, you'll have to modify to suit.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.