How to perform Cross platform testing and Cross browser testing using QTP? Can u explain giving some example?

You will need to create separate Actions which take care of different OS and Browsers

Cross Platform Testing : Using the Built in Environment Variable you can dig up the OS information.

Ex : Platform = Environment(“OS”). Then based on the Platform you need to call the actions which you recorded on that particular platform.

Cross Browser Testing : Using this code Ex : Browser(“Core Values”).GetROProperty(“version”) you can extract the Browser and its correspondin version. Ex : Internet Explorer 6 or Netscape 5. Based on this value you call the actions which are relevant to that browser.