The requested url /em is not found on the server

During the navingation of Application Server enterprise manager in the SOA Suite, i received a message that ' The requested url /em is not found on the server'

The Cause is that:
During installation of SOA Suite, mistakenly i forgot to check the "Configure this as an Administration OC4J instance".

So the Enterprise Manager control is not enabled in our SOA Suite,
Everything is turned off after this, i had the fix from here
Fix:
The two files you need to touch:
ORACLE_HOME/j2ee/oc4j_soa/config/server.xml
ORACLE_HOME/j2ee/oc4j_soa/config/default-web-site.xml

The values you need to change from the files:
In server.xml find ascontrol and set start="true"
in default-web-site.xml find ascontrol and set ohs-routing="true"
Restart SOA
$ORACLE_HOME/opmn/bin/opmnctl stopall
$ORACLE_HOME/opmn/bin/opmnctl startall

The requested web page should appear now.

Cheers!!!