Skype SIP: xinit, command not found

I am trying to use Skyp with a sip connection as shown in the following article

When I try and run xinit (as mentioned in step 1), I get “command not found” X appears to be installed so how do I achieve what they are asking?

How can we possibly assist you with the little information you provided? What distribution are you trying to do this on?

Hi I used asterisk now ISO

eport bugs to [email protected][email protected] ~]# uname -a
inux localhost.localdomain 2.6.18-194.11.1.el5 #1 SM
Tue Aug 10 19:09:06 EDT 2010 i686 i686 i386 GNU/Lin
[email protected] ~]#