java.lang.Exception: IOException in sending Request :: Connection refused: connect

Hi all,
I am new to Oracle 10g.I am using Enterprise manager for DBA jobs.After logging in to enterprise manager, when i click the refresh button, i get the folllowing error
" java.lang.Exception: IOException in sending Request :: Connection refused: connect"

Please do help to slove this problem. :confused:

Thanks

Do you get this error only when you do the refresh? Are you able to connect to Enterprise manager the first time? Is the database up and running?