Using Li element for get/post

I found this at w3 schools PHP tutorial but see it represents a Select html box and options and my site has UL, List/Li Elements that had < a tags with href and target attributes. I've stripped the jewelry UL of it's Li

< a tags and want to know how to get the Li oncklick to get the database table to change the 'f1' div innerHTML.

w3 School

http://www.w3schools.com/php/php_ajax_database.asp

The function

function showUser(str)
{
if (str=="")
 {
 document.getElementById("txtHint").innerHTML="";
 return;
 } 
if (window.XMLHttpRequest)
 {// code for IE7+, Firefox, Chrome, Opera, Safari
 xmlhttp=new XMLHttpRequest();
 }
else
 {// code for IE6, IE5
 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
 }
xmlhttp.onreadystatechange=function()
 {
 if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
 }
xmlhttp.open("GET","getuser.php?q="+str,true);
xmlhttp.send();
}

I have addEvent in mockup.js like so

var jewelrylist=document.getElementById('jewelrylist');
var jewelry=jewelrylist.getElementsByTagName('li');
var silver=jewelry.item(1);
function getsilver(text)//Changed from 'str'
{
if (silver.text=="Silver")//the li element text
 {
 document.getElementById("f1").innerHTML="";//the div id I want to change
 return;
 } 
if (window.XMLHttpRequest)
 {// code for IE7+, Firefox, Chrome, Opera, Safari
 xmlhttp=new XMLHttpRequest();
 }
else
 {// code for IE6, IE5
 xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
 }
xmlhttp.onreadystatechange=function()
 {
 if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("f1").innerHTML=xmlhttp.responseText;
}
 }
xmlhttp.open("GET","getSilver.php?s="+str,true);//don't know if this file goes in the www folder?
xmlhttp.send();
}
addEvent(silver,'click', getsilver(); }, false);//Should work??  

My HTML UL ID jewelrylist

<ul id="jewelrylist">
<li id="jewelry" class="top" title="The Most Beautiful Jewelry Made in Mexico!">Jewelry</li>
<li class="item" title="Silver Jewelry Made in Mexico!">Silver</li>
<li class="item" title="Silver & Gold Jewelry, Made in Mexico!">Silver & Gold</li>
<li class="item" title="Silver Jewelry with Stones, Made in Mexico!">Silver & Stones</a>
</li>
</ul>

getSilver.php Not sure what folder to put this in, www or php?

<?php
$s=$_GET["s"];
$con=mysql_connectmysql_connect('localhost','root','root');//default for Uniserver??
if(!con){die('Not connected:'.mysql_error( ));}
mysql_select_db("wbi",$con);//mydb
$sql="SELECT*FROM silver WHERE Id='".$s."'";//table silver has 2 test rows
$result=mysql_query($sql);
while($row = mysql_fetch_array($result))//might have to add some splits for Set types in rows?
{
echo "<div id='rowcell" . $row['Id'] . "' class='rowcell'>";
echo "<div id='imagecell" . $row['Id'] . "' class='imagecell' align='center'>";
echo "<a id='imageref" . $row['Id'] . "' class='imageref'"; echo "href='" . $row['Href'] . "' title='Take a Closer Look then Press Your"; 
echo "Back Button to Return'><img src='" . $row['Src'] . "'/></a></div>";

#end of .imagecell continues verbosley

I know I'll have to use INCLUDE mydb.php and filtering to make it more secure but I'd like to get it tried before I start modifying the other ULs. Any advise greatly appreciated. Also let me know if this is an inappropriate forum for this topic