Issue with Datasink values getting populated to excel.

Hi,
I m populating datasink values through groovyscript and executing the datasink step using "testRunner.runTestStepByName('DataSink')"
.Have enabled the datasink step too.If i disable that step values won't be populated to excel sheet.If it is enabled then the duplicate values are getting populated in excel sheet.Please help in solving this issue.I m using soapui pro version.

Thanks in advance.
Sowmya