Blank Web Page
When you met a blank PHP page on the browser, you might have no clue in the first place. But there was a possibility that the PHP page has errors but httpd server showed nothing instead of debug message.
The key property in /etc/php.ini to show the errors on the client is the directive "display_errors" which is "Off" by default on Linux for production servers.
You can change the value for development purposes.
[root@localhost ~]# vi /etc/php.ini
display_errors = On
Don't forget to restart httpd server to take effect.
[root@localhost ~]# service httpd restart
Stopping httpd: [ OK ]
Starting httpd: [ OK ]
If you are sure that you have already turn on display_errors, there's only one possible left. Your program did have errors in the run-time, but you suppressed the errors somewhere in the code by "@" signs. Please check your code for sure.