Hi !!!
I think I have the solution inspired by this
Add this javascript function just after the function search(lim):
[code:1]
function clearForm(formIdent)
{
var form, elements, i, elm;
form = document.getElementById
? document.getElementById(formIdent)
: document.forms[formIdent];

if (document.getElementsByTagName)
{
elements = form.getElementsByTagName('input');
for( i=0, elm; elm=elements.item(i++); )
{
if (elm.getAttribute('type') == "text"«»)
{
elm.value = '';
}
}
}

// Actually looking through more elements here
// but the result is the same.
else
{
elements = form.elements;
for( i=0, elm; elm=elements[i++]; )
{
if (elm.type == "text"«»)
{
elm.value ='';
}
}
}
}
[/code:1]

Then replace :
[code:1]
<input type=\"reset\" value=\"reset\">
[/code:1]
By :
[code:1]
<input type=\"button\" value=\"reset\" onclick=\"clearForm('ricerca')\">
[/code:1]

For now, it works very well for me... If somebody finds any bug, thanks to report it.

Praetorian.

It seems to be the only solution...
Great Job!

Thanks,
Francesco

Just want to inform everybody here there's another advanced search, but this one is a components. Biggest advantage is that no hacks are necessary. Just install the component and enable which fields are to be searchable.
Look in this forum: www.joomlapolis.com/component/option,com_joomlaboard/Itemid,38/func,view/catid,20/id,8736/
website: www.emptorum.com