[R] Generate Dendrogram

[farscape2012]

Hi

I have a distance matrix which is computed by user defined method. I 
would like to plot the dendrogram. I would like to use different color 
and want the leaves laying down bottom.
The script like this. I am not familiar with R. I followed the example 
shown in 
http://stat.ethz.ch/R-manual/R-devel/library/stats/html/dendrogram.html

dist.obj <- as.dist(matrix.distance)
hc.obj <- hclust(dist.obj,method="ave")
dend1 <- as.dendrogram(hc.obj)
plot(hc.obj, xlab='',ylab='',sub='', nodePar=list(pch = c(1,NA), 
cex=0.8, lab.cex = 0.8)).

But I got warning and the plot does not look like what I wanted.

Warning messages:
In plot.hclust(hc.obj, xlab = "", ylab = "", sub = "", nodePar = 
list(pch = c(1,  :
   "nodePar" is not a graphical parameter

It also can not recognize

edgePar=
dLeaf=
edge.root

Does someone know what's wrong?

Br,
Luffy