Adam,
The VALUE of the form element will be whatever is sepcified for the value attribute of the option that is selected. From the code you posted, the values are correct in the HTML code. All you need to do is used ad_page_contract which takes the query variables passed by the browser and sets Tcl variables with the same names in your Tcl page.
Please note, which you called the form element "person_names" the code you show has the value as the person_id of the person for each selection, not their name. The name is used for display in the select box only.
