how do I change pl/sql code to create a multi select instead of list box

I have the following code:

htp.p('            <td valign="top" align="left">');
htp.p('            <div id="org_users2">');
htp.p('            <select  class="form_field_select_400" id="item_assigned_to_id2" name ="item_assigned_to_id2');
htp.p('             <option  />');
htp.p('              </select>');


I want to format the web application as a list box. How would I modify this code so that it appears as a list
Can I use <div class="listbox-area">