CraftBukkit Fail to bind to Port error

does anyone know what i can do for this kind of error? i have tried setting the server.properties IP address setting to my home public IP, tried to port forward, and have also set the IP as a blank field. Any suggestions? Here is the Error message:

||15:56:11 [WARNING] **** FAILED TO BIND TO PORT!||
||15:56:11 [WARNING] The exception was: java.net.BindException: Can't assign requested address||
||15:56:11 [WARNING] Perhaps a server is already running on that port?||

 

Have you ever made any other servers and tried to port forward them? "Perhaps a server is already running on that port?||". You probably didn't port forward correctly. Try this.

http://portforward.com/ , Also make sure all of you're server files are setup the right way. Try this.