how do get oracle agent to start up

For Oracle there is always a log.

Check under: agent10g/sysman/log

You can also try starting it from a command prompt:
emctl start agent

This should provide additional information.

>>I have a database 10.2.0.5 and I installed Oracle agent

Did you install a different agent before you created the database and told it to use Grid Control?

I installed the agent then I created the database the agent is 10.2.0.3 version  

there is a trace file that has entries like
2012-05-23 19:47:34 Thread-45 ERROR pingManager: nmepm_pingReposURL: Did not receive a response header from repository

THe emctl.log has entries like
28557 :: Mon May 21 16:03:19 2012::AgentStatus.pm:Processing reload
28557 :: Mon May 21 16:03:19 2012::AgentStatus.pm:emdctl status agent returned  3
28557 :: Mon May 21 16:03:26 2012::AgentStatus.pm: emdctl reload returned with exit code 0
28610 :: Mon May 21 16:03:30 2012::AgentStatus.pm:Processing reload
28610 :: Mon May 21 16:03:31 2012::AgentStatus.pm:emdctl status agent returned  3
28610 :: Mon May 21 16:03:38 2012::AgentStatus.pm: emdctl reload returned with exit code 0
562 :: Wed May 23 19:41:56 2012::AgentLifeCycle.pm: Processing start agent
562 :: Wed May 23 19:41:57 2012::AgentLifeCycle.pm:status agent returned with retCode=1
562 :: Wed May 23 19:42:05 2012::AgentLifeCycle.pm: Exited loop with retCode=3

I don't understand this info

What version is the database?

>>Did not receive a response header from repository

Any other errors?

database is 10.2.0.5

i think that is the problem when I check the agent status or try to start the agent the header looks like this

Oracle Enterprise Manager 10g Database Control Release 10.2.0.5.0
Copyright (c) 1996, 2010 Oracle Corporation.  All rights reserved.
---------------------------------------------------------------
Agent is Not Running


when I execute runInstaller and check installed products it shows agent installed version 10.2.0.3

I have a variable AGENT_HOME and it is pointing to the directory where the agent is installed and I also have the agent_home/bin directory in the path variable

My Oracle_home is pointing to the oracle database

Have you tried using the 10.2.0.5 agent?  For grins I would uninstall everything 10.2.0.3 and stay with 10.2.0.5.

I've never used Grid Control outside of class but going from memory, the 10.2.0.5 agent should know how to talk to a 10.2.0.3 Grid install.

ironically now it is pointing to the right emctl and the agent has started. but now it shows the upload manager as disabled and the grid control doesn't show the database server. It is suppose to see it automatically but it doesn't

It has been many years since I messed with Grid Control.

Can you not go into Grid Control and 'Discover' the node?

I tried i keep getting response that grid automatically sees or discovers host

I found this website that suggested removing a lot of files

http://www.oracleangels.com/2011/07/disabled-by-upload-manager-emctl-status.html

then I went to the grid website and now I see the server

thanks for your server

sorry thanks for your help

Glad to help, even though you more or less fixed it yourself...