Dialog refuses to open as modal

[devnull]

Even though I have set the dialog modal to true, and have also tried setting it's options.modal = true before opening, it simply refuses to open as modal.

How can I track down why this might be ?

Code:

  $('#_query_').dialog({
    modal: true,
    title: 'My Modal',
    width: 400,
    height:'auto',
    closed:true,
    iconCls:'icon-filter'
  })

var dl = $('#_query_');
dl.dialog('open');
dl.dialog('move',{left:50,top:50});
dl.dialog('options').modal = true;

Thanks

[stworthy]

Please refer to this example http://jsfiddle.net/kadLfs6k/. It works fine.

[devnull]

Hi;

Yes, I know it works fine in a simple page, but something is preventing it from being modal, and I was asking how I can find out why it is not modal.