Is it possible to add containment (confining to the boundary of another element) to jQuery UI's Dialog?
See Question&Answers more detail:os@Mottie's on the right track, but there's a simpler and better solution:
var container = $('.dialog-container'),
dialog = $('.ui-dialog');
dialog.draggable( "option", "containment", container );
Unlike Mottie's solution, this will not break if the viewport resizes. I've forked the JSFiddle here.