How to allow Drop Down listbox to accept null values/no value

[A-doobie12]

How do you get a drop down list box to accept null as its value, without "Allowing Custom Text Entry" ?

In other words I want my list box to have values of:

Apple

Orange

Pear

Peach

Null

[pguerett]

You can add an entry with a space in it or you can type the word null to represent no selection

Paul

[JohnBrinkman]

You can have an entry in the list to represent no value ("<none>").

Then you can add an exit script that looks like:

if (this.rawValue === "<none>") {
    this.rawValue = null;
}

This way, when the user selects the "<none>" entry, the value will be set to null when they exit the field.

   John