Hi,
As no one replied to my this problem but i got the solution so i m posting it here.
Actually when we change the Deploymentdescriptor file from WebLogic Console it updates the in-memory deployment descriptor only. so when u restart the server changes will be lost and it won't be applied on jar file on Local Disk.
to make the changes permanent i mean in memory and the Deployment descriptor on DISC, we need to
Click the root element of the tree in the left pane. The root element is the either the name of the
EJB JAR archive file or the display name of the EJB.
Then in right pane u will get Two Buttons one is
Validate and another is Persist.
Click Validate to to ensure that the entries in the EJB deployment descriptors are valid.
Click Persist to write your edits of the deployment descriptor files to disk in addition to WebLogic Server memory.