Go Back via JavaScript and PHP

Use this simple code as a button that will return users to the previous page:

<form>
 <input type="button" value="Return to previous page" onClick="javascript:history.go(-1)" />
</form>

Here it is as a simple text link:

<p>
 <a href="javascript:history.go(-1)" title="Return to the previous page">&laquo; Go back</a>
</p>

You can make things easier by serving PHP and printing the link automatically. Here is the button link:

echo "<form><input type=\"button\" value=\"Return to previous page\" onClick=\"javascript:history.go(-1)\"></form>";

And here is the PHP code to print a "Go back" text link:

echo "<p><a href=\"javascript:history.go(-1)\" title=\"Return to previous page\">&laquo; Go back</a></p>";

Better yet, you can kick the accessibility factor up a notch by using PHP’s inherent HTTP_REFERER variable to write explicitly the previous URL, thereby eliminating the JavaScript requirement (thanks to Rick Beckman for the idea):

<?php $referer = $_SERVER['HTTP_REFERER'];
   if (!$referer == '') {
      echo '<p><a href="' . $referer . '" title="Return to the previous page">&laquo; Go back</a></p>';
   } else {
      echo '<p><a href="javascript:history.go(-1)" title="Return to the previous page">&laquo; Go back</a></p>';
   }
?>

The previous code will create an explicit "Go back" link when the referring URL is known. In those awkward situations where no referring URL has been recognized, the function writes a "Go back" link via JavaScript.