When adding new scripts to your site it is necessary to set specific permissions for the script to work. 

The Linux directory and file structure has a system of permissions. You have permission to read a file, you have permission to write to a file, and finally, you have permission to execute a file. However, you are not always you. 

Linux splits identities into three categories. The first is you, the owner of the file. The second is the group you belong to. And third, others is the world, basically anyone who comes to your website. 

To change permissions you must issue a "change mode command", or more commonly referred to as the 'NIX command "chmod". The documentation for your file or script will usually come with instructions that contain the proper permissions you need to set for your program to work. To set permissions, there are basically 2 methods available on your GlowHost server, via a good ftp program like WS_FTP or Cute_FTP or from the file manager in your control panel.