Nginx + php-fpm page display blank problem

This afternoon configuration nginx+php environment, ready to put a WordPress play. But after the layout of the page PHP page has been blank, at first I thought it was a matter of permissions, the right to change to 755 after still not. Then I opened the Nginx and PHP log, but in the log there is no response to anything wrong. Continue trying to change the PHP log without effect. After going home at night, I continued to try for a long time, and finally found out that it was Nginx's configuration file that wrote less than one configuration message.

Fastcgi_param script_filename $document _root$fastcgi_script_name;

Because of the lack of this configuration information, so that Nginx did not send to resolve the PHP file address to PHPFPM, so the page has been blank, there is no resolution of the error message.