This depends on your operating system and the type and version of your browser:
PC running Windows using Internet Explorer v5+:
Press and hold the ALT key, press the Access Key and then press ENTER.
PC running Windows using Internet Explorer v4.x:
Press and hold the ALT key, press the Access Key of your choice.
PC running Windows using Netscape v6+ or Mozilla:
Press and hold the ALT key, then press the Access Key of your choice.
Macintosh computer using Internet Explorer v5+
Press and hold Control and then press the Access Key.