Web Ringtone Maker in Ajax

I am looking to create a simple Ringtone maker in Ajax. Basically you upload the music file (mp3/wav/mp4/aac/midi/m4a) Then you can select the Time interval to crop with an option to select a FadeIn/Fadeout if you would like. Please check out: [login to view URL] and [login to view URL] I think the best way to describe this is cropping a sound file (selecting 2 time intervals to crop from and to) with the ability to add "increasing volume from mute" in the beginning (fadein) and "decreasing volume to mute" (fadeout). This is a web application written in Ajax. If it can be done with other programming language let me know.