Here is a code snippet used to solve it. I used the selection option "Other" at the bottom of the list and when it is selected you get an input box which adds the item. The listbox uses the item number as the variable result of a selection. Code is inserted in the "Selection Changed" area for the listbox. If Single item selection is used, it leaves the new item selected when done.
Code: Select all
ListBoxGetItem "InfoFrom" "[InfoFrom]" "[selectedfromitem]"
If "[selectedfromitem]" "=" "Other"
InputBox "AA information from" "Who contacted you about this Alert" "[InfoFrom2]"
If "[infofrom2]" "<>" ""
ListBoxChangeItem "InfoFrom" "[infofrom]" "[InfoFrom2]"
ListBoxAddItem "InfoFrom" "0" "Other"
Endif
Endif