Calling ggplot from function

Question

Consider the following:

df <- data.frame(a=1:10,b=2:11)
ggplot(df,aes(x=a,y=b)) + geom_point()+geom_text(aes(label=a,x=a+0.1))

This works.

However for some reason the following doesn't work:

plotGG <- function(data,shift) {
  ggplot(data,aes(x=a,y=b)) + geom_point()+geom_text(aes(label=a,x=a+shift))
}
plotGG(df,.1)

Any clues??