To create your first PHP page, you’ll start exactly as you would if you were creating an HTML document from scratch. Understanding the reason for this is vitally important: Web browsers are client applications that understand HTML; PHP is a server-side technology, which cannot be run in the client. To bridge this gap, PHP will be used on the server to generate HTML that’s run in a Web browser.
There are 2 main differences between a standard HTML document and a PHP document.
First, PHP scripts should be saved with the .php file extension (for example, index.php).
Second, you place PHP code within <?php and ?> tags, normally within the context of some HTML:
...
<body><h1>This is HTML.</h1>
<?php PHP code! ?>
<p>More HTML</p>
...
Relocating users
PHP also provides a method to move a user from one page to another in your Web site without requiring the user to click a link or a button. You can send a message to the Web server that tells it to send a new page by using the PHP header statement. The format of the header function that sends the user to a new page is as follows:
header("Location: URL");
The header statement sends the message, Location: URL, to the Web server. In response, the file located at URL is sent to the user’s browser. Either of the following statements are valid header statements:
header("Location: newpage.php");
header("Location: http://company.com/catalog/catalog.php");
The header function has a major limitation. The header statement can only be used before any other output is sent. You can’t echo output — such as some HTML code — to the Web page and then send a message requesting a new page in the middle of the script.
Refreshing the current page
To refresh the current page just use:
$curPage = $_SERVER['PHP_SELF'];
header("Location:$curPage");