If you get nothing but a blank screen on your browser, it may be because there is a script error. Turn on debugging at the start of your script:
localhost problems / Vista 64 bit
Since updating to Windows Vistax64bit for development, all files containing images or external stylesheets crashed or timeout.
See the useful thread at: http://www.wampserver.com/phorum/read.php?2,28291
To generate images and retrieve external stylesheets, mPDF needs to access files using fopen() etc. Changing “localhost” to “127.0.0.1” resolved the problem.
Generating graphs with JPGraph
JPGraph outputs error messages as images generated by the script. If the error message is “out of memory” then you just get a blank screen. Try increasing your memory_limit.