I'm not entirely sure what you mean by 'make an online shoutcast web player' - do you mean an embeded player connected to your Shoutcast stream?
It's fairly simple- I had one on my MySpace page a while back when I was streaming a Shoutcast server. It was a simple WindowsMedia Player embed pointed to my Shoutcast address, which is your IP.
If this isn't what you mean, can you be more specific? Anyone can connect to your Shoutcast page by navigating to your IP through HTTP if you're streaming.