[jQuery] UI Dialog: Need the ID of the clicked button...

[discern]

Because I am using the CLASS of the button to open UI Dialog (as
opposed to the ID), how can I pass it the ID (or any data, for that
matter)? I need to pass the ID of the button to dialog so I know which
row to apply the actions of the dialog to.

var opt = {
        autoOpen: false,
        modal: true,
        buttons: {
                'Show ID': function() {
                        alert("ID: "+id); // < I want to at least get this far
                },
                Cancel: function() {
                        $(this).dialog('close');
                }
        },
};

$("#new").dialog(opt);

$('a.button').click(function() { // Because I am using CLASS not ID to
open UI Dialog (I have to; I am using this for several rows)
        var id = $(this).attr('id').split('_')[1]; // This is the ID. How can
I pass it to UI Dialog?
        $('#new').dialog('open');
});