HTML program difficulty in arduino MEGA 2560 with Wifi shield

I have an arduino mega 2560 board and a Arduino Wifi shield. The Basic Arduino programs involving Wifi shield are working properly with my board and shield.

I am trying to create a login page with password for providing access to the actual program page using html in the program. I use Arduino IDE 1.0.5. Kindly guide me and provide me a code which i can include in my WiFi shield program so as to create a login page before viewing the actual program which is being executed by the arduino board. This is for security reason as i dont want everyone having the IP address displayed by my board to access my program and my page.

Thank You

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