Adding functionality to the existing website

I have a web site working fine and happy the way it is. I like to add a functionality to the website section "Meet The Maidens" Website Link - [login to view URL] Functionality Required: When some one clients on the team member image on Meet the Maiden section It should ask for a password and when the password is entered the flower image flips and the real image of the team member comes up . One password will be used for all the team members . Please advice how long it would take to create the functionality. I am a developer myself and just do not have enough time to do the task myself . Please mention " Karachi" in your bid so i can know you read the brief till the end and understands the scope of the project. Looking forward to start immediately . Thank you