The requested URL /phpmyadmin was not found on this server

When I was restarting the apche2, I was getting this message..

sudo service apache2 restart
 * Restarting web server apache2                                                                                                                AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1. Set the 'ServerName' directive globally to suppress this message

and when I was typed the localhost/phpmyadmin, it showing the message

-NOT FOUND The requested URL /phpmyadmin was not found on this server. Apache/2.4.7 (Ubuntu) Server at localhost Port 80

Please help me in this.