How to get bubbles on times series plot

Hi;
lissage<-function(variable)
{
    library(pastecs)
    ENTREE.ts <- ts(projet$ENTREE)
    ENTREE.dec <- decaverage(ENTREE.ts, order=variable,  sides=2,
ends="fill")
    plot(ENTREE.dec, col=c(1, 4), xlab="temps",ylab="Nombre
d'entr?es",main=paste("Moyenne mobile d'ordre ",variable," sous R"),
stack=FALSE, resid=FALSE,
    lpos=c(50, 12.3))
}
lissage(100)
My code gives this:
http://n4.nabble.com/file/n1008225/mb.png 
but i want that:
http://n4.nabble.com/file/n1008225/mboriginal.png 
I can't find the option to change into bubbles.
Can you help me? Thanks.