use two plugins

use two plugins

i try to use both two plugins : a datepicker ui.datepicker.js and a tree jquery.treeview.js

each works well, but i can't have them on the same page ?

'cause i declare twice ready.function() ... and there not the same ...

$(document).ready(function(){
$("#arbo").treeview({collapsed: true});
});
$(document).ready(function(){
$("#date_in").datepicker({
firstDay: 1, });
});

how use two or more jquery plugins ?