Not able to delete all child data

Question

Hi
I would like to delete all existing data in Child Form, but the below code is deleting just one record.
What am I missing here..
public void RemoveProcessFormChildData(long pKey, tcDataProvider tcdp){
          try
     tcFormInstanceOperationsIntf f = (tcFormInstanceOperationsIntf)tcUtilityFactory.getUtility(tcdp, "Thor.API.Operations.tcFormInstanceOperationsIntf");
     tcResultSet childFormDef = f.getChildFormDefinition(f.getProcessFormDefinitionKey(pKey),f.getProcessFormVersion(pKey));
     long childKey = childFormDef.getLongValue("Structure Utility.Child Tables.Child Key");
     String plChildTableName = childFormDef.getStringValue("Structure Utility.Table Name");
     logger.info("Child Key::"+childKey);
     logger.info("Child table name: "+plChildTableName);
     tcResultSet childFormData = f.getProcessFormChildData(childKey, pKey);
     logger.info("No. of records in Child Form::"+childFormData.getRowCount());
     for(int i=0;i<childFormData.getRowCount();i++)
          long plChildFormPrimaryKey = childFormData.getLongValue(plChildTableName + "_KEY");
          logger.info("Child Form Primary Key::"+plChildFormPrimaryKey);
          f.removeProcessFormChildData(childKey, plChildFormPrimaryKey);
     logger.info("After calling RemoveChildData()");
          catch(Exception e)
               logger.info("Exception Occured::"+e);
Thanks

Answer 1

forgot to add the below line :)
lookupRes.goToRow(i);