Loading database content via XMLHttpRequest in Wordpress

[admin]

I have created a new wordpress-template-page. The idea is, that when I click on a link in my sidebar-div, it should load content from an database in my content-div. On a simple php-page it works, but in combination with my wordpress template-page it doesn't work...

And that's my code: (short version)

<?php // Template Name: Weinkarte
get_header(); ?>

<div id="container-sidebar">
     <span id="wineList"></span>
</div>

<div id="sidebar-right">
    <li><a href='#' id='1' onclick='loadWine(this.id)'>Click</a></li>
</div>

get_footer();

<script>
function loadWine(id)
{
xmlhttp=new XMLHttpRequest();
xmlhttp.onreadystatechange=function()
  {
  if (xmlhttp.readyState==4 && xmlhttp.status==200)
    {
    document.getElementById("wineList").innerHTML=xmlhttp.responseText;
    }
  }
xmlhttp.open("GET","loadWine.php?landID="+id,true); //I think here is probably the fault
xmlhttp.send();
}
</script>

Thanks for any help!