jquery and js-methods

jquery and js-methods

hi,
i'me new to jquery and what i didn't got is interaction of jquery und js-methods.
my problem:
i use the jq-plugin jstree.
the code:
  1. $(function () {
    $("#async_json_2").tree({
    opened : ['sid0'],
    ui : {
    theme_name : "classic"
    },
    callback: {






    beforedata: function (NODE, TREE_OBJ) {return { parent_id : $(NODE).attr("id") || "NULL" } },...
with $(NODE).attr("id") i get the value of the attribute 'id', wich is f.e. "sid0". But what I need is only the integer-part of this value so i need "0" in this case. In js i would define something like ...id.replace(/sid/, ''); but $(NODE).attr("id") .replace(/sid/, ''); doesn't work.
How do I do s.t. like that in JQ ?
thank you for help an
best,
heinetz