[R] xyplot: Plotting two variables, one as points - the other as line. Can that be done without explicitly using panel functions

[Søren Højsgaard]

Hi! Consider
d <- data.frame(x=1:10,y=5+1:10, yf=rnorm(10,5+1:10)) 
    x  y        yf
1   1  6  5.268621
2   2  7  8.623896
3   3  8  8.114830
4   4  9 10.125955
5   5 10  9.977261
...
 
I plot y and yf against x with 
 
xyplot(y+yf~x,data=d,col=c('red','green'),pch=c("a","b"))

BUT - I would like that the plot of y against x is with type='l' and the plot of yf against x is with type='p'. 
 
1) Can this be done easily (i.e. without panel functions)? (Doing
 
  xyplot(y+yf~x,data=d,type=c("l","p"),col=c('red','green'),pch=c("a","b"))
 
is not the way ahead) 
 
2) How to do it with panel functions?
 
Thanks in advance
Søren