for redundancy of EM service i used name (emlogin) instead of the ip address of the server in the following EM link.
and because there is no dns server and ip address configuration is manual so i configured router as my dns server and used follwing configuration on it.
Router (config)# ip dns server
Router (config)# ip host emlogin <ip address of 1st ccm> <ip addr of second ccm> "
and i am only entering the dns server ip manualy on the phone ( i have not configured it on callmanager server). but when on the phone i select services and chose EM it gives me "host not found" instead of userid and pin.even though i have changed hostname to ip address in enterprise parameter. am i missing something? or i have configured it incorrectly?