no server connected after change theUME configuration in Dual satck install

Hi all,

we installed Bi system wit BI java and with was java and was abap.As with BI java automatically installs with EP and EP core.I logged to Ep system with administrator id .In UME configuration sap system tab I changed the client to 600 where all my users are there.Initially it was 001 .I changed the systemname from localhost to my hostname .I tested the connection .It worked.After restarting the server i am not able to login into the EP part of the system.

It is throwing the error

503 service unavailable.

Dispatcher running but no server connected!

How to get back the connection .Please help me.It is very urgent.

regards,

rajesh