How to design and use the data sheet in a Script

If Dialog("Login").Exist Then
'Login to the application
Dialog("Login").WinEdit("Agent Name:").Set DataTable("LoginUid", "FlightR-WinApplication")
Dialog("Login").WinEdit("Password:").SetSecure DataTable("LoginPwd", dtLocalSheet)
Dialog("Login").WinButton("OK").Click


What is data table, Local Sheet? How to design a data sheet and how to use it in the script?

DataSheet is used for getting parameterized data to the script.In QTP there are two inbuild datasheets one is global-Used across the actions and local-used only to that specified action.There is a concept to use external datasheet also like excel etc.,

in ur code "Dialog("Login").WinEdit("Agent Name:").Set DataTable("LoginUid", "FlightR-WinApplication") "

LoginUid - will be the field name of the datasheet
FlightR-WinApplication - Ur Action Name

From the FlightR-Window Action datasheet it will pick up the parameterized data from the LoginUid field and supply to the application "Agent Name" filed.