Data driven testing using excel in QTP

This is script for data driven using excel sheet.
In this script we are not importing excel sheet to datatable. Directly values are supplied to application from excel sheet.

set ex= CreateObject("Excel.Application")
Set a=ex.Workbooks.open("D:\excel.xls")
Set b=a.worksheets("Sheet1")

dim login, pwd

for i=1 to 3

login=b.Cells(i,"A").value
pwd=b.Cells(i,"B").value
msgbox login
msgbox pwd

next

"D:\excel.xls" is path of excel sheet.
"sheet1" indicates sheet name in which values are present.
A,B are column names in excel sheet.

we have excel sheet with values as shown below in d drive.
A B
1 2
3 4
5 6