See this at: javascriptkit.com| Added on 05/12/08

And once called by external JavaScript: In the above, we have a normal PHP script that writes out the IP address of the visitor when referenced using external JavaScript, with two important details: * A JavaScript header is sent at the very beginning... See more

And once called by external JavaScript: In the above, we have a normal PHP script that writes out the IP address of the visitor when referenced using external JavaScript, with two important details: * A JavaScript header is sent at the very beginning to inform the page that our PHP script is outputting a JavaScript file. * Since the final output of our PHP script needs to be a valid .js file, whatever the PHP outputs must conform to valid JavaScript syntax. So to display the IP address from the perspective of JavaScript, the echo function above includes "document.write()" as part the content to send back to the page. Notice how I didn't output the JavaScript script tag itself (), as just like inside a regular .js file, this isn't required nor valid. The ability to reference a PHP script inside your external JavaScript can be very useful! It means your JavaScript now has access to once exclusive information on the server side, whether it's the server time, the visitor's IP address, a... See less