This error message usually springs up in a previously functional PHP script when the memory requirements exceed the default 8MB limit. Don’t fret, though, because this is an easy problem to overcome.
To change the memory limit for one specific script by including a line such as this at the top of the script:
ini_set("memory_limit","12M");
The 12M sets the limit to 12 megabytes (12582912 bytes). If this doesn’t work, keep increasing the memory limit until your script fits or your server squeals for mercy.
You can also make this change permanently for all PHP scripts running on the server by adding a line like this to the server’s php.ini file:
memory_limit = 12M