Thank you very much for your help.
I have downloaded check_url.pl and put as a service but it seems not working.. i think i am jumping it to high level without checking simple things first.
So i decided to configure a service check_ssh to monitor a remote server's ssh
My configuation seems fine for the check_ssh, pre-flight goes fine. But i am receiving the following error messages in the log file and emails
 SERVICE NOTIFICATION: nagiosadmin;test1.test1.com;SSH;CRITICAL;notify-service-by-email;CRITICAL - Socket timeout after 20 seconds
Any idea how to resolve this.
check_ssh test1.test1.com in a command line gives proper output.