CTL + ALT + SHIFT +1

OK, I saw an email with the key sequence CTL+ALT+SHIFT+1 in the subject so I tried it. I happen to have the mouse focus in the Netscape Mail reading the email. To my suprise the text changed to what looked like non-english text. Entering the sequence again the text switched back to normal. Can anyone explain this? Thanks, Terry -- SuSE Linux 7.3 (i386) 2.4.16-4GB Wed Jul 10 19:55:00 CDT 2002 7:55pm up 5 days, 22:48, 1 user, load average: 0.12, 0.10, 0.09