Example of JavaScript

The important pieces:

Reference an external javascript file. The javascript functions in this file can now be used within the page. <html> <script src="example7.js" type="text/javascript"> return true; </script>
The "example7.js" contains a function ValidateForm. The ValidateForm function checks to see if the email input box is not empty and if the string matches the format of an email address. function ValidateForm(thisform) { /* calls isNotEmpty and isEmailAddress */ } function isNotEmpty(elem) { /* function to check if element is not empty */ } function isEMailAddr(elem) { /* function to validate form of email address */ }
onsubmit attribute of form element. This is an "event attribute". <form action="http://minerva.dce.harvard.edu/cgi-bin/echo.cgi" onsubmit="return ValidateForm(this)">