Execution Error on My Value Provider

This is first time to write a value provider.
But got Error during 'work item save'. What's the problem and the solution to it?
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dojo.provide("com.example.js.ProjectCodeCalculator");

(function() {

dojo.declare("com.example.js.ProjectCodeCalculator", null, {

getValue: function(attribute, workItem, configuration) {

var parentAttribute = configuration.getChild("parentAttribute").getIdentifier();
var parentValue = workItem.getValue(parentAttribute);

return "G" + parentValue;
},

__sentinel: null
});

})();
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Project Configuration as follows..
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<valueProvider>
<script>
<parentAttribute>
</valueProvider>
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The Error message on Jetty Server ....
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14:41:29,976 ERROR com.ibm.team.workitem.common - Error invoking value provider 'com.ibm.team.workitem.valueproviders.VALUE_PROVIDER._eZAxAFEZEeCvsvFM8pRlgg'
org.mozilla.javascript.JavaScriptException: ({"Bundle-SymbolicName":"org.dojotoolkit.dojo", "path":"resources\\_base\\_loader", "name":"loader.js"}#414)
at org.mozilla.javascript.gen.c2._c18({"Bundle-SymbolicName":"org.dojotoolkit.dojo", "path":"resources\\_base\\_loader", "name":"loader.js"}:413)
at org.mozilla.javascript.gen.c2.call({"Bundle-SymbolicName":"org.dojotoolkit.dojo", "path":"resources\\_base\\_loader", "name":"loader.js"})
at org.mozilla.javascript.ContextFactory.doTopCall(ContextFactory.java:401)
at org.mozilla.javascript.ScriptRuntime.doTopCall(ScriptRuntime.java:3003)
at org.mozilla.javascript.gen.c2.call({"Bundle-SymbolicName":"org.dojotoolkit.dojo", "path":"resources\\_base\\_loader", "name":"loader.js"})
at com.ibm.team.rtc.common.scriptengine.environment.dojo.DojoFeature$3.call(DojoFeature.java:179)
at org.mozilla.javascript.ScriptableObject.callMethod(ScriptableObject.java:1862)
at com.ibm.team.rtc.common.scriptengine.environment.ScriptingHelperImplementation$4.run(ScriptingHelperImplementation.java:141)
at com.ibm.team.rtc.common.scriptengine.environment.ScriptingHelperImplementation$4.run(ScriptingHelperImplementation.java:1)
at com.ibm.team.rtc.common.scriptengine.environment.AbstractScriptEnvironment.execute(AbstractScriptEnvironment.java:74)
at com.ibm.team.rtc.common.scriptengine.environment.ScriptingHelperImplementation.dojoRequire(ScriptingHelperImplementation.java:138)
at com.ibm.team.rtc.common.scriptengine.environment.ScriptingHelperImplementation.getConstructor(ScriptingHelperImplementation.java:151)
at com.ibm.team.rtc.common.scriptengine.ScriptUtilities$1.run(ScriptUtilities.java:30)
at com.ibm.team.rtc.common.scriptengine.environment.AbstractScriptEnvironment.execute(AbstractScriptEnvironment.java:74)
at com.ibm.team.rtc.common.scriptengine.ScriptUtilities.newInstance(ScriptUtilities.java:27)
at com.ibm.team.workitem.shared.common.internal.valueProviders.ScriptAttributeValueProvider.getProvider(ScriptAttributeValueProvider.java:93)
at com.ibm.team.workitem.shared.common.internal.valueProviders.ScriptAttributeValueProvider.getValue(ScriptAttributeValueProvider.java:52)
at com.ibm.team.workitem.common.internal.attributeValueProviders.AttributeValueProviderRegistry$SafeValueProvider.getValue(AttributeValueProviderRegistry.java:43)
at com.ibm.team.workitem.common.internal.model.impl.AttributeImpl.getValue(AttributeImpl.java:899)
at com.ibm.team.workitem.service.internal.save.DependentValueUpdater.handleNotifySave(DependentValueUpdater.java:40)
at com.ibm.team.workitem.service.internal.save.WorkItemSaveParticipant.handleNotifySave(WorkItemSaveParticipant.java:32)
at com.ibm.team.workitem.service.internal.save.WorkItemSavePreparation.notifySave(WorkItemSavePreparation.java:198)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService.notifyPreSave(WorkItemRepositoryService.java:323)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService.access$2(WorkItemRepositoryService.java:317)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService$1.run(WorkItemRepositoryService.java:235)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService$1.run(WorkItemRepositoryService.java:1)
at com.ibm.team.repository.service.internal.TransactionService$2.run(TransactionService.java:200)
at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$Transaction.run(RepositoryDatabase.java:440)
at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase$1.run(RepositoryDatabase.java:267)
at com.ibm.team.repository.service.internal.rdb.ConnectionPoolService.withCurrentConnection(ConnectionPoolService.java:332)
at sun.reflect.GeneratedMethodAccessor62.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy61.withCurrentConnection(Unknown Source)
at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runTransaction(RepositoryDatabase.java:263)
at com.ibm.team.repository.service.internal.rdb.RepositoryDatabase.runInTransaction(RepositoryDatabase.java:219)
at com.ibm.team.repository.service.internal.TransactionService.runInTransaction(TransactionService.java:119)
at com.ibm.team.repository.service.internal.TransactionService.runInTransaction(TransactionService.java:88)
at sun.reflect.GeneratedMethodAccessor164.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy105.runInTransaction(Unknown Source)
at com.ibm.team.repository.service.AbstractService.runInTransaction(AbstractService.java:947)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService.saveTransaction(WorkItemRepositoryService.java:227)
at com.ibm.team.workitem.service.internal.WorkItemRepositoryService.save(WorkItemRepositoryService.java:185)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy417.save(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleMethod(AbstractTeamServerServlet.java:1276)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.executeMethod(AbstractTeamServerServlet.java:872)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.doPost(AbstractTeamServerServlet.java:661)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest2(AbstractTeamServerServlet.java:1834)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.handleRequest(AbstractTeamServerServlet.java:1688)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.access$0(AbstractTeamServerServlet.java:1673)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet$1.service(AbstractTeamServerServlet.java:195)
at com.ibm.team.repository.internal.service.auth.impl.JAuthHandler.handledRequest(JAuthHandler.java:123)
at sun.reflect.GeneratedMethodAccessor136.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.invoke(ExportProxyServiceRecord.java:370)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord.access$0(ExportProxyServiceRecord.java:356)
at org.eclipse.soda.sat.core.internal.record.ExportProxyServiceRecord$ExportedServiceInvocationHandler.invoke(ExportProxyServiceRecord.java:56)
at $Proxy477.handledRequest(Unknown Source)
at com.ibm.team.repository.servlet.AbstractTeamServerServlet.service(AbstractTeamServerServlet.java:1545)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.eclipse.equinox.http.registry.internal.ServletManager$ServletWrapper.service(ServletManager.java:180)
at org.eclipse.equinox.http.servlet.internal.ServletRegistration.handleRequest(ServletRegistration.java:90)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.processAlias(ProxyServlet.java:111)
at org.eclipse.equinox.http.servlet.internal.ProxyServlet.service(ProxyServlet.java:75)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:502)
at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:380)
at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:181)
at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:417)
at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
at org.mortbay.jetty.Server.handle(Server.java:324)
at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:535)
at org.mortbay.jetty.HttpConnection$RequestHandler.content(HttpConnection.java:880)
at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:748)
at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:213)
at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
at org.mortbay.jetty.bio.SocketConnector$Connection.run(SocketConnector.java:228)
at org.mortbay.jetty.security.SslSocketConnector$SslConnection.run(SslSocketConnector.java:636)
at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:520)

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