[jQuery] Jquery Xml and XPath

I am trying to load an xml , and then to query the xml through xpath.

I am trying to load an xml, and then to query it using xpath.

i've tried this:

$.ajax({
type: "GET",
url: "Menu.xml",
dataType: "xml",
success:
function(xml)
{
    $(xml,'/Root/Item').each(...);

}
}

<Root>
    <Item ID="1"></Item>
    <Item ID="2"></Item>
    <Item ID="3"></Item>
    <Item ID="4"></Item>
</Root>

This returns me 0.

But if i change it to

    $(xml,'Root>Item').each(...);

it works.

But i need to make "real" xpath queries.

PLz help me