Bug on soapui

import java.io.File;
import jxl.*;
import jxl.write.*

Workbook wb
WritableWorkbook workbook
WritableSheet sheet
def Label label
def row = 0
def col = 0

def excelfile = new File("D:/books/write.xls")

if(!excelfile.exists()) {
 //if it does not exist, crate it and write to the first row
 workbook = Workbook.createWorkbook(excelfile)
 sheet = workbook.createSheet('SheetName', 0)

 label = new Label(0, row, 'Exp_Value')
 sheet.addCell(label)
 label = new Label(1, row, 'Response_Value')
 sheet.addCell(label)
 label = new Label(2, row, 'test_status')
 sheet.addCell(label)
 row++;
} else {
 wb = Workbook.getWorkbook(excelfile)
 workbook = Workbook.createWorkbook(excelfile, wb)
 sheet = workbook.getSheet('SheetName')

 //if it does exist, write some values
 row = sheet.getRows()

 number = 1

 (1 .. 3).each {
  (0 .. 2).each {
   column ->
   label = new Label(column, row, number.toString())
   sheet.addCell(label)
   number++
  }

  row += 1
 }
}




workbook.write()
workbook.close()

if (wb != null)
{
 wb.close()
}