Add the following code to the document you want to use the script in (before any calls to the functions defined in the script):
<script type="text/javascript" src="form_validation.js"></script>
If the form_validation.js file is in a different directory than the html document, be sure to include the relative path to the Javascript file in the src attribute value.
Have a nice day.
This script is released under a Creative Commons License.
