Build a Website

Hi, so basically what i want is a youtube to mp3 converting website, users come enter the youtube url hit convert and get the converted file in high mp3 format instantly no wait at all, has to be instant like this website [login to view URL] I have already designed the website so you don't have to worry about that, all you need to do is to create the back-end, the text box where people enter the url and hit convert and get the link to download. The text box should exactly be like this website has it [login to view URL] the eg link is there and when they click it to enter the url the text disappears. When users convert the video lets say for eg this is the link they converted [login to view URL] so after conversion it should display Video successfully converted to mp3 Title: John Martin - Anywhere For You Download Now and when they click download it should download in that title name. You will help me integrate the text box into my webpage and help me setup the website on a dedicated server aswell.. The website should be made in java script only and create it in a way so that i don't encounter any scaling problems for a good period of time and if there are any problems in the future i want the same guy who created the script to fix it so only bid if you can help me in the future. i will pay you of course for it.. I need good professional work done so if you haven't done many projects or if you'r rating is not that good please don't bid for the project. Thanks.