This tutorial shows how to put OsCommerce site under maintenance.
In order to put site under maintenance, reach your server files via FTP or through cPanel.
Back up index.php (it is located in the root of your site folder), i.e. save a copy of it on your computer.
Open index.php with any code editor (Notepad++, Sublime, DreamWeaver, etc.):
Replace the code with simple html code inserting the text that indicates that the site is under construction at the time:
You can use plain html code like <h1>We are temporally closed…</h1>, use your own code and styles or use the ready maintenance page code from the sites like http://www.webtechelp.net/:
Save the changes you have made.
Refresh the site to see your maintenance page instead of the home page:
Feel free to check the detailed video tutorial below: