Change sectiob name

Hi
anyone can help me to change a section name.

this is my code

ReportSectionController rsc = (ReportSectionController) targetdoc.getReportDefController().getReportSectionController();

Section sec = (Section) targetdoc.getReportDefController().getReportDefinition().getReportHeaderArea().getSections().getSection(0);

sec.setName("newsec");
rsc.setProperty(sec, ReportSectionPropertyEnum.name, "newsec");

and i got the exception:

Exception in thread "main" com.crystaldecisions.sdk.occa.report.lib.ReportSDKServerException:
Error in File C:\WINDOWS\TEMP\{17521592-C3FE-47BA-954E-1AC519C2A2AF}.rpt:
Invalid section.-- Error code:-2147483130 Error code name:failed
at com.crystaldecisions.sdk.occa.report.application.PrintOutputController.export(Unknown Source)
at com.crystaldecisions.sdk.occa.report.application.PrintOutputController.export(Unknown Source)
at SetSec.main(SetSec.java:89)

Thanks!
[999 byte] By [maor] at [2007-11-20 9:12:32]