title: Html: For Select multiple, only one value is submitted but .val() returns array of two values
body: <p>When rendering the page, the <code>val()</code> of a multiple select is set with a single value. For example, <code>$("#my_select_box").val(1);</code> 
  Then the user selects an additional value in the multiple select box. </p>
  
  <p>When the form is submitted, only the newly selected value is submitted and not the previously set one. Whereas while debugging in Firefox, the <code>.val()</code> function returns an array of two values (both the previous one and the newly selected one). Why does this happen?</p>