Personas: How to determine if item is in a DropDown

In a script, how can I check if an item is in a dropdown list?  Sometimes the item will exist, other times it won't.

Example:  The dropdown list will not always contain HTTPS entries.  How to I check for its existence?  I tried to test for "Control Exists" but that did not work.

Here is the tail end of the object:  ... /dropmenuTTYP/menuCONTEXT/itemTT66.

Any ideas?

1st time posting so I hope I've got the correct area and the question is pertinent.

Thanks.