The interface has changed, the property is now named 'tagname'.

print_r($root) is your friend if you can't find what you're searching for (and the source of course).

Closing.

Thanks, but that doesn't solve my problem yet.
I used print_r($root)and indeed I can see that property changed name to "tagname". But thereis is no property "content".I use this xml document:

<?xml version=\"1.\">
<me><name>JoeCool</name><age>24</age><sex>male</sex></me>

And then I do
 $docTree = xmltree($myXML); (where $myXML contains the xml)
 print_r( $docTree );
 
What I get is: 

Array
(
    [0] => DomElement Object
        (
            [type] => 1
            [tagname] => name
            [0] => 3
            [1] => 137743960
        )

    [1] => DomElement Object
        (
            [type] => 1
            [tagname] => age
            [0] => 4
            [1] => 137744104
        )

    [2] => DomElement Object
        (
            [type] => 1
            [tagname] => sex
            [0] => 5
            [1] => 137744248
        )

But there is no property "content" like in older versions of libxml. How can I get the value of name, age and sex ?I 've 
searched the site php.net and there is no informations about any changes in libxml interface.

Documentation has not been updates because domxml is still experimental. Domxml now (or, it should) conform to the DOM2 API.

Try going for the children() nodes of the 'name' element.

Btw, my output with 4.1.0 looks like:

DomDocument Object
(
    [name] => 
    [url] => 
    [version] => 1.0
    [standalone] => -1
    [type] => 9
    [compression] => -1
    [charset] => 1
    [0] => 1
    [1] => 136076352
    [children] => Array
        (
            [0] => DomElement Object
                (
                    [type] => 1
                    [tagname] => me
                    [0] => 2
                    [1] => 136076472
                    [children] => Array
                        (
                            [0] => DomElement Object
                                (
                                    [type] => 1
                                    [tagname] => name
                                    [0] => 3
                                    [1] => 136076560
                                    [children] => Array
                                        (
                                            [0] => DomText Object
                                                (
                                                    [type] => 3
                                                    [content] => JoeCool
                                                    [0] => 4
                                                    [1] => 136076632
                                                )

                                        )

                                )

                            [1] => DomElement Object
                                (
                                    [type] => 1
                                    [tagname] => age
                                    [0] => 5
                                    [1] => 136076704
                                    [children] => Array
                                        (
                                            [0] => DomText Object
                                                (
                                                    [type] => 3
                                                    [content] => 24
                                                    [0] => 6
                                                    [1] => 136076776
                                                )

                                        )

                                )

                            [2] => DomElement Object
                                (
                                    [type] => 1
                                    [tagname] => sex
                                    [0] => 7
                                    [1] => 136076848
                                    [children] => Array
                                        (
                                            [0] => DomText Object
                                                (
                                                    [type] => 3
                                                    [content] => male
                                                    [0] => 8
                                                    [1] => 136076920
                                                )

                                        )

                                )

                        )

                )

        )

)

You were obviously missing some important information.