n-nodes recursive tree

Hi, I have an xml file which looks pretty much like this:
<tree>
        <node>
                <id>1</id>
                <parent>root</parent>
                <node>
                        <id>4</id>
                        <parent>1</parent>
                </node>
                <node>
                        <id>5</id>
                        <parent>1</parent>
                        <node>
                                <id>7</id>
                                <parent>5</parent>
                        </node>
                </node>
        </node>
        <node>
                <id>2</id>
                <parent>root</parent>
                <node>
                        <id>6</id>
                        <parent>2</parent>
                </node>
        </node>
        <node>
                <id>3</id>
                <parent>root</parent>
        </node>
</tree>

In effect, i will never know the max number of levels in tree node, and so i'd 
like to obtain an html file formated with xsl and wich looks like that:

Tree
    ---- 1
            ---- 4
            ---- 5
                    ---- 7
    ---- 2
            ---- 6
    ---- 3
        
I don't know recursive tools that provides XSLT and if there is anyway to do 
that. Does anybody know what can i do about this? 

Thanks very much,

 XSL-List info and archive:  http://www.mulberrytech.com/xsl/xsl-list