"all.plot" <-
function (x=allprice, mfrow=c(2,2), ask=TRUE) 
{
	on.exit(par(oldpar))
	oldpar <- par(no.readonly=TRUE)
	par(ask=ask, mfrow=mfrow)

	for(i in 1:ncol(x)) {
		plot(x[, i], type="l", xlab="Days", ylab="Price",
			main=colnames(x)[i])
		abline(v=500)
	}
}
"early.plot" <-
function (x=earlyprice, ask=TRUE) 
{
	on.exit(par(oldpar))
	oldpar <- par(no.readonly=TRUE)
	par(ask=ask)

	for(i in 1:ncol(x)) {
		plot(x[, i], type="l", xlab="Days", ylab="Price",
			main=paste("Series:", colnames(x)[i]))
	}
}
"late.plot" <-
function (start=1, end=100, ask=TRUE) 
{
	on.exit(par(oldpar))
	oldpar <- par(no.readonly=TRUE)
	par(ask=ask, oma=c(0,0,1,0), mfrow=c(2,2))

	if(start < 1 || start > 100) stop("bad value for start")
	if(end < 1 || end > 100) stop("bad value for end")
	if(start > end) stop("start is larger than end")

	real.start <- 4 * (start - 1) + 1
	real.end <- end * 4

	for(i in real.start:real.end) {
		plot(lateprice[, i], type="l", xlab="Days", ylab="Price",
			main=colnames(lateprice)[i])
		if( i %% 4 == 0) {
			mtext(side=3, outer=TRUE, paste("Series:",
				colnames(earlyprice)[round(i/4)]))
		}
	}
}