Ajax style Hiermenu

source: http://www.commentcamarche.net/forum/affich-1498208-onchange-dans-un-select

//ds head
<script language='javascript'>
function RendVisibleVille(texte)
{
if (texte=="autre")
document.getElementById("test").style.visibility= 'visible';
else
document.getElementById("test").style.visibility= 'hidden';
}
</script>


//ds body

<FORM ACTION="index.php" name="formulaire">
<SELECT size=1 onchange="RendVisibleVille(this.value)" name=select_ville >
<OPTION value="paris">Paris</OPTION>
<OPTION value="marseille">Marseille</OPTION>
<OPTION value="metz">Metz</OPTION>
<OPTION value="autre">autre</OPTION>
</SELECT>

<div id="test" style="visibility:hidden">
<input type="text" name="ville_saisie"></div>
<input type="submit">
</form> 

exemple: http://radeff.red/info/forms/hierSelectAjaxStyle.html