Drop Down Menu - drop down menu with java script

I'm implementing a drop down menu to be used with various products so that I can save some space in the products section of this particular site.

Here's an example of the java:
<SCRIPT LANGUAGE='JavaScript' TYPE='text/javascript'>

<!--

if (document.images) {

Ilogo = new Image(100, 17);Ilogo.src='images/something_home.gif' ;

Ilogo_over = new Image(100, 17);Ilogo_over.src='images/something_home_over.gif' ;

;}

function di(id,name) {

if (document.images) {

document.images[id].src=eval(name+".src");}}

// -->

</SCRIPT>

--------------------------
Here's an example of the drop down:
<form name="herbals">

<span class="indexHead">Herbals</span><br>

<select name="item" onChange ="go(document.herbals.item)">

<option value="">Select one...

<option value="herbals/acuity.html">Acuity Plus

<option value="herbals/alfalfa.html">Alfalfa Tabs

<option value="herbals/dtx.html">DTX

<option value="herbals/echinacea.html">Echinacea Complex

<option value="herbals/garlic.html">Garlic

<option value="herbals/gla.html">GLA Plus

<option value="herbals/moodlift.html">Moodlift

<option value="herbals/optiflora.html">Optiflora

<option value="herbals/osteokinetics.html">Osteokinetics

<option value="herbals/saw_palmetto.html">Saw Palmetto Plus

<option value="herbals/valerian.html">Valerian Plus

</select><br>

<span class="indexBody">Formulas you can trust</span>

</form>

<p></p>

--------------------------------------
I thought this would be fairly simple but I'm stumpped on it.

Could someone give me a bit more info on this script/drop down and let me know how 2 set it up?

Thanks for the time!!!!