With Jquery, I'm looping through the attribute named tags, in each <option> of the <select> dropdown below.
You'll see I would LOVE to have 2 of the options preselected, if the number 6 exists in the tags attribute.  
<select name="someFun" id="someFun"  multiple="multiple">
  <option value="1" tags="4,6,7">something</option>
  <option value="44" tags="2">something</option>
  <option value="61" tags="1,3,6">something</option>
  <option value="44" tags="2">something</option>
</select>
<script language="javascript" type="text/javascript">
$(document).ready(function(){
  var preselectedtag = '6'; // auto select any with 6
  $("#someFun > option").each(function() {
     var tag = $(this).attr("tags");
     /* change attr of this option to "selected" if 6 exists in var tag */
  });
});
</script>
I could use some help here. Is there a best way to do this?
In PHP I normally use an in_array() function, but javascript seems way more picky.