Most of the code in this book so far is very well explained but I have hit a roadblock on p178 (I get a little lost with the do's and the sequence in delete.php)

if ( !isset( $_GET['do'] ) || $_GET['do'] != 1 ){
?>
      <p align="center" style="color:#FF0000">
         Are you sure you want to delete this <?php echo $_GET['type']?>?<br/>
         <a href="<?php echo $_SERVER['REQUEST_URI']?>&do=1">yes</a> or <a
href="index.php">Index</a>


I understand conceptually what is going on here but I can't create a variation of it since I do not understand why the href approval takes pace after the !isset???

It's checking to see if the $_GET query string variable "do" is set. If not, It's displaying a link to either delete the item, or return to the index. Notice in the href attribute of the link, "do" is set to 1. If you clicked on the link and it posted back to this page, the link choice would not display again, because do would be set, and its value would be 1.

In other words, the isset() function and comparison to 1 wrap the link, to only show it when needed.