adding significance codes and error bars on paired bar plot

#1
Hello,

I have a dataset like so..
Code:
structure(list(meanvalue = c(0.38172, 0.8684, 0.854675, 0.907025, 
0.7551, 0.9726, 0.99575, 0.80785, 0.45462, 0.719575, 0.64908, 
0.613333333333333, 0.9972, 0.70095), day = 1:14, random = c(0.336, 
0.336, 0.336, 0.336, 0.336, 0.336, 0.336, 0.336, 0.336, 0.336, 
0.336, 0.336, 0.336, 0.336)), .Names = c("meanvalue", "day", 
"random"), row.names = c(NA, -14L), class = "data.frame")
and a graph like the one attached, where it is a paired bar graph..

The code I used for the graph is from the data above and is as follows:
Code:
mp<-barplot(meanrandom, beside=TRUE, axisnames=TRUE, names.arg=mn$day)
I would like to add an asterisk if the difference is significant ( < .05), and also error bars.. Can I do this in the barplot function? or do I have to find the values and then add them as text?

Thank you,

Ross
 
#3
So I have been working in ggplot2.. And now I have an error message that reads

'Error in rename(x, .base_to_ggplot, warn_missing = FALSE) :
could not find function "revalue"'

It seems the ads() function is not working or my packages are somehow not correct with the version I have.. I can't figure it out, has anyone else had this problem?