Script error when closing IE window / tab with the Quick Plot preview dialog open in Ajax viewer

[wuma]

In Ajax Viewer, if we close the IE browser's window or tab while the Quick Plot preview dialog is still open, there will be a script error.

It happens only in IE with compressed jxlib.js. The reason is, quickplotpanel page has a unloade event handler which will close the preview dialog. The event handler invokes the PreviewDialog.cancel() to close the dialog. While cancel() just "fades out" the dialog to have a good visual effect. In IE, the web page will be closed before the "fade out" process finishes, then an error will occur.

The solution is: don't use "fade out" effect. Instead, just completely remove the Jx.Dialog element from mapFrame. A method PreviewDialog.dispose() is implemented to do this.