You need to alter your httpd.conf file.
You should find something like this in the file:
<VirtualHost **YOUR IP**>
ServerAlias **YOUR DOMAIN **YOUR DOMAIN**
ServerAdmin **YOUR EMAIL ADDRESS**
DocumentRoot /home/*YOUR USERNAME**/public_html
BytesLog domlogs/*YOUR DOMAIN**-bytes_log
<IfModule mod_php4.c>
php_admin_value open_basedir "/home/**USERNAME**/:/usr/lib/php:/usr/local/lib/php:/tmp"
</IfModule>
<IfModule mod_userdir.c>
UserDir disabled
UserDir enabled *username*
</IfModule>
ServerName **DOMAIN NAME**
User *username*
Group *username*
CustomLog domlogs/*domain* combined
ScriptAlias /cgi-bin/ /home/*username*/public_html/cgi-bin/
</VirtualHost>
Where it says **YOUR DOMAIN **YOUR DOMAIN**
Type:
your ip
www.yourdomain.com yourdomain.com
So it should look something like this:
123.23.12.123
www.domain.com domain.com