jQuery Forum

$('#myDialog').dialog( { modal:true, resizable:false } ).parent().find('.ui-dialog-titlebar-close').hide();

It's better to use .dialog( "widget" ) instead of .parent(). This has more semantic meaning and will work even if the markup structure for dialogs changes.

Hiding is simple. There is another little problem with close button: insert both icon (in sprite) and close text. With current markup it is hard:

<a href="#" class="ui-dialog-titlebar-close ui-corner-all"><span class="ui-icon ui-icon-closethick">Close</span></a>

and this is better:

<a href="#" class="ui-dialog-titlebar-close ui-corner-all"><span class="ui-icon ui-icon-closethick"></span>Close</a>