video chat program

hi, i want to create video chat api . Two person communicate each other via video chat on [login to view URL] use this programming language: PHP or HTML,javascript or C#.NET. There isnt necessary css design etc. Just video chat functionality must be in this program. Scenario: Two people have constant url link etc. When one person click the own url link, send notification to another one and call to video chat . After another user click to own url and two people will see each other on screen then use video chat and talk each other. Best regards, Baran