Immediately after calling DoList, the property 'Result' will tell you what the user did. You can say:
get the result
If it is empty, then the user clicked on the Cancel button. Otherwise, item 1 of it will be the number of items selected. If you are setting
<Flag> to be 'ONE' then this number will always be 1. Otherwise, it will be any number from zero to the number of items in the list. Once check this to find out how many items there are, you can use them in any way you wish. For example, if the user selected 1 item from the list, and you want to put this item into a container named 'choice' :