How to set jQuery UI dialog defaults

I found a solution

$.extend($.ui.dialog.prototype.options, { modal: true, width: 650 });

There's no built-in functionality for that AFAIK, but what I usually do is set them myself in a separate hash like this:

var dialog_defaults = {
  autoopen: false,
  buttons: {
    close: function() { $(this).dialog('close'); }
  }
};

Then when I create the dialog, I use jQuery's extend method to make them work, like this:

$('#divvie').dialog(
  $.extend({}, dialog_defaults, {
    autoopen: true
  })
);

The second set of arguments you pass in will overwrite/merge with whatever's in the dialog_defaults variable. Just make sure you put the empty hash ({}) in there, or your defaults will get overwritten, that's bitten me in the past.