CGI: Plot mult-station time series

I created a quick web interface for plotting time series from multiple weather stations on the same plot. See here: http://home.chpc.utah.edu/~u0553130/Brian_Blaylock/cgi-bin/plot_ts_multistations.cgi

The code to create this is on github:
The web interface: https://github.com/blaylockbk/Web-Homepage/blob/master/cgi-bin/ts_multistations.cgi
The plotting function: https://github.com/blaylockbk/Web-Homepage/blob/master/cgi-bin/plot_ts_multistations.cgi