=== TC 1 ===
 1. Open Iframe dialog
 1. Enter URL, height and width and press OK
  * Iframe is added into edit area
 1. Open context menu and select IFrame properties 
  * In opened dialog, all previously enetered values are in he right place
 1. Close dialog, switch to source and back, open iframe properties again.
  * After switching modes, all properties should be in right place.