pp.timelinefill <-
function (x, type="l", log="y", fillcol="blue", main="", ...) 
{
	## simple-minded function to plot time series
	## with filling using a line connecting start and end
	## placed in the public domain by Burns Statistics 2011
	##

	if(inherits(x, "zoo")) {
		plot(x, type=type, log=log, main=main, ...)
		px <- c(index(x), index(x)[1])
		py <- c(as.vector(x), as.vector(x)[1])
		polygon(px, py, col=fillcol)
	} else {
		stop("not implemented for objects that are not 'xts' or 'zoo'")
			}
}