734c734,741
< 			
---
>                         #check if the re is a valid one
> 			try:
>                             dummy=re.compile(regex)
>                         except:
>                             dialog = gtk.MessageDialog(type=gtk.MESSAGE_ERROR, flags=gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT, buttons=gtk.BUTTONS_OK, message_format=_("Provided regular expression is not valid."))
>                             dialog.run()
>                             dialog.destroy()
>                             return 
758c765,773
< 		
---
> 		#check if the re is a valid one
>                 try:
>                     dummy=re.compile(new_text)
>                 except:
>                     dialog = gtk.MessageDialog(type=gtk.MESSAGE_ERROR, flags=gtk.DIALOG_MODAL | gtk.DIALOG_DESTROY_WITH_PARENT, buttons=gtk.BUTTONS_OK, message_format=_("Provided regular expression is not valid."))
>                     dialog.run()
>                     dialog.destroy()
>                     return 
>