from here
Basically, you need to increase the size of the following values above what you want your maximum value to be (except for upload_max_filesize which you can keep at exactly what you want the limit to be). Here, we want our max file size to be 10MB.
memory_limit = 32M
upload_max_filesize = 10M
post_max_size = 20MOf course these go in your php.ini file which is usually in something like “/etc/php5/apache2/php.ini” or equivalent/similar file path.