How to change jQuery dialog html content after init?

I have a working dialog, and i want to change the content during the flow of the app, I mean to change the .html() property of the dialog...

I thought it was easy to do but i can't seem to do:

$dialog.dialog().html(SOME CONTENT);

How do I do that after I already have the dialog running?

My init code is:

var $dialog = $('<div></div>')
    .html(SplitTable)
    .dialog({
        autoOpen: false,
        height: 500,
        width: 600,
        title: 'פיצול שולחן'});

    $dialog.dialog('open');

where is the ID in that? this is the what i understood i should do from the examples, didn't see any Id property...

p.s. splitTable is the content that i need to change during to program to updatTable...

10x