I made a simple script for plotting BR growth using the Monte Carlo method. The script works fine. Then I added a form for a user to be able to enter parameters. This script however only displays a missing image symbol only. Could someone give me some suggestion what might be the cause of that?

Here are the scripts:
http://pastebin.com/MshyXczE
http://pastebin.com/aXRGirVc

It requires PHPlot library. Copy the files into a folder named "phplot".
http://downloads.sourceforge.net/pro..._mirror=freefr