How to configure DHCP in CentOS to use

How to configure DHCP in CentOS to use 

Check current IP configration of eth0. It is seen that IP address has not been assigned.

ifconfig eth0

Then, the contents of eth0 configuration file is viewed using 'cat' command.

cat /etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE="eth0"
HWADDR="00:xx:xx:xx:xx:xx"
NM_CONTROLLED="yes"
ONBOOT="no"

vi is used to modify the configuration to be like this.

DEVICE="eth0"
BOOTPROTO="dhcp"
HWADDR="00:xx:xx:xx:xx:xx"
NM_CONTROLLED="yes"
ONBOOT="yes"