dynamically push multidimensional array in php from xml

I want to create a multidimensional array based on an xml file. the file only includes menu,menu->link and menu->submenu,menu->submenu->link. I want an multidimensional array to be looked like this.

array()  
0=>menu1  
  0=>submenu1  
  1=>sublink1  
1=>link1  
2=>menu2  
  0=>submenu1  
  1=>sublink1
  2=>submenu2  
  3=>sublink2
3=>link2  
....  
....  

the xml code is given here:

<page> 
  <title>Examination Remuneration</title>  

  <menu title ="Home" link="http://">  
    <submenu title="About" link="#">  
    </submenu>  
  </menu>  

  <menu title ="Data Entry" link="http://">  
    <submenu title="Form 1" link="#">  
    </submenu>  
    <submenu title="Form 2" link="#">  
    </submenu>  
  </menu>  
</page>  

what i have tried:

<?php  
  $main = simplexml_load_file("MENUU.xml");  
  $allmenu = array();  
  foreach ($main->menu as $menu) {  
    array_push($allmenu,$menu["title"]);
    foreach($menu->submenu as $submenu){  
         //dont know what to do here :(
    }
    array_push($allmenu,$menu["link"]);
  }
  var_dump($allmenu);
?>  

The problem is I cannot find how to push multi dimension and another problem is I dont know how many submenu a menu can have. Any kind of help is appreciated and TIA.