establish a connection to the server netbeans

Question

I have a problem with the netbeans7.3.1 when ever I try to run my php program i get this error from the browser : Unable to connect

Firefox can't establish a connection to the server at localhost:8000.

my interpreter location is : /usr/bin/php5

The project configuration : PHP Built-in Web Server (running on built- in web server) my operating system is : Ubuntu linux.

I've been having this problem for more then 6 months now, I've looked and searched everywhere but I could not find the solution for this.

Just to mention that I had another problem with the interpreter it used to ask me to locate the interpreter every time i run netbeans , but i fixed this by installing php5.