[R] two questions about PLOT

[Jie TANG]

here ,I want to plot two lines in one figure.But I have two problems
1) how to move one of the y-axis to be the right ? I tried to the
command"axis(2)",But I failed.
2) how to add the axis information correctly.Since I have use the cmommand
"axis(1,at=1:6,labels=gradeinfo$gradenam)"
   but it seems that the correct information that I want is superposition
with the old axis information.What can i do ?
the script and figure is shown as below .thanks .:)

outflnm<-paste(Outdic,"meansd.jpg",sep="/")
jpeg(file=outflnm, bg="transparent")
legend<-c("average error","stand quare error")
lgcol<-c("black","red1")
par(las=1)
yylab<-c("forecast error")
xxlab<-c("typhoon class")
llty<-c(1,3)
llwd<-c(4,4)
#par(bg='yellow')


plot(avegrp,type='l',lty=1,col='black',lwd=4,xlab=xxlab,ylab=yylab)
par(new=T)
plot(sdgrp,type='l',lty=3,col='red1',xlab=xxlab,ylab=yylab,lwd=4)
#axis(2, col = "gold", lty = 2, lwd = 0.5)
legend("topright", legend,   lty=llty, lwd=llwd,col =lgcol)
axis(1,at=1:6,labels=gradeinfo$gradenam)
dev.off()

-- 
TANG Jie
Email: totangjie at gmail.com
Tel: 0086-2154896104
Shanghai Typhoon Institute,China