Mark said:
			
		
	
	
		
		
			That will generate a message asking the user to confirm that they want
to close the window, and you have omitted the final semi-colon.
The correct JavaScript is:
"window.opener=null;window.close();"
		
		
	 
That only appears to be the case with IE6.
In IE7, setting opener to null doesn't appear to make a difference.  There
is a difference between closing a window that was opened by script versus
closing a window that was not opened by script.  You're prompted with a
confirmation if closing a window that was _not_ opened by JavaScript.  If
the window was opened by JavaScript, you're not prompted with a confirmation
(it just closes).  Setting window.opener to null doesn't change this.
In Firefox, if you try to close a window that was not opened by JavaScript,
it doesn't close and you get the message "Warning: Scripts may not close
windows that were not opened by script." in the error console.  If you close
a window that was opened by JavaScript, you're not prompted with a
confirmation (it just closes).  This is true regardless of setting
window.opener to null.
In Safari 3.1, setting opener to null makes no difference.  Windows opened
by script always close without a confirmation, and windows not opened by
script will not close with window.close().