R help - Oct 2008 - Error in X11

Hello everyone,

I'm trying to plot a graphic in Linux, when I type X11() then I have an
error which is the next: Error in X11(d$display, d$width, d$height, d$pointsize,
d$gamma, d$colortype,? :
?unable to start device X11cairo

?
Why?, what I must do to fix it?. Thanks so much
?
Carlos