can anybody correct this script? 1) i cannot paste here the entire script line by line and i had to separate the commands by semicolumns 2) the script diplays the output NULL and i dont understand why 3) sorry im a complete dummy ad i found this script on a journal

#!/usr/bin/env Rscript; 
outputfile <- paste ("linear", ".png", sep=""); 
png(filename=outputfile, width=1600, height=1200); 
x <- c(0,1,2,3,4,5,6,7,8,9,10); y <- c(2,5,6,7,8,10,11,20,14,25,30); 
p <- plot(x,y,pch=19); #First degree equation 
fit <- lm(y~x) 
print(p); 
lines(x,predict(fit,data.frame(x=x)),col="red"); 
invisible(dev.off())