create tree from arrays

hi all, I want to create an array from another array to create json file in my format and pass it to a js library....ok. I just know that I have to use recursive function... but how? it's hard for me to create the new array.. main array: Array ( [0] => Array ( [nid] => 1 [parentID] => 0 [text] => Dashboard [cls] => x-btn-icon [icon] => lib/extjs/resources/images/default/icon/Dashboard.png [singleClickExpand] => 1 [leaf] => 0 [id] => Dashboard ) [1] => Array ( [nid] => 2 [parentID] => 1 [text] => Dashboard [cls] => firstExpanded [icon] => lib/extjs/resources/images/default/tree/s.gif [singleClickExpand] => 1 [leaf] => 0 [id] => ) [2] => Array ( [nid] => 3 [parentID] => 2 [text] => Dashboard [cls] => x-btn-icon [icon] => lib/extjs/resources/images/default/tree/s.gif [singleClickExpand] => 1 [leaf] => 1 [id] => dashboard ) ........... ---------------------- The array I want to create: ---------------- [0] => Array ( [nid] => 1 [parentID] => 0 [text] => Dashboard [cls] => x-btn-icon [icon] => lib/extjs/resources/images/default/icon/Dashboard.png [singleClickExpand] => 1 [leaf] => 0 [id] => Dashboard [children] => Array( [0] => Array ( [nid] => 2 [parentID] => 1 [text] => Dashboard [cls] => firstExpanded [icon] => lib/extjs/resources/images/default/tree/s.gif [singleClickExpand] => 1 [leaf] => 0 [id] => [children] => Array( [0] => Array ( [nid] => 3 [parentID] => 2 [text] => Dashboard [cls] => x-btn-icon [icon] => lib/extjs/resources/images/default/tree/s.gif [singleClickExpand] => 1 [leaf] => 1 [id] => dashboard ) ) ) ) ) ......... wow! it means that by nid and parentID, I'll notice where I must add children item to array... Thanks, Shahrzad