Line Graph in php

Anybody help me for creating line graph in php using mysql data?
I have made bar graphs using phpgraphlib but in case of line graph,
there will be no output.
In my data i want to take time scale in yaxis,may be this is a problem.
Because i searched for this but i got examples where time scale are in xaxis.
Plz help me how to take time scale in y axis.

You can use canvas and .svg files to make line graphs, or any other kind
of graph. For .svg a polyline should work well. You can also make a
background for the graph.

if you're lucky, you might have gnuplot installed on your server (or you can always request it to be installed)
http://www.gnuplot.info
you can plot whatever you want and however you want using that.