无法读取Excel中的值，没有执行循环里的内容，找不到原因，求解！

Question

FilePath = Environment ("TestDir") & "\data.xls"
Set ExcelBook = CreateObject("Excel.Application")
Set ExcelSheet = CreateObject("Excel.Sheet")
Set myExcelBook = ExcelBook.WorkBooks.Open(FilePath)
Set myExcelSheet = myExcelBook.WorkSheets("sheet1")
GetExcleSheetRowsCount = myExcelSheet.UsedRange.Rows.Count
For i=2 to GetExcleSheetRowCount
systemutil.Run "C:\Program Files\Mercury Interactive\QuickTest Professional\samples\flight\app\flight4a.exe","","",""
Dialog("Login").WinEdit("Agent Name:").Set myExcelSheet.cells(i,1).value
Dialog("Login").WinEdit("Password:").Set myExcelSheet.cells(i,2).value
Dialog("Login").WinButton("OK").Click
window("Flight Reservation").Close
wait(3)
Next
ExcelBook.quit
Set ExcelSheet = Nothing
Set ExcelBook = Nothing