jquery how to Completely delete the progress bar or dialog

jquery how to Completely delete the progress bar or dialog

I added a progressbar when my app raise ajax application, this progress
bar was prompted by a dialog, I write below code in ajaxStop function:
progressbarDialog.dialog("close");
progressbar.progressbar("close");
this.appendDOM.empty(); `
It works well when the first ajax happens, but from the second time, a
dialog and progresss bar display un-normal, a blank part will show under
the normal part, I think the dialog may be not deleted but hided, can
anyone explain this issue? how can the dialog/progress bar total be
deleted?