Writing the Validation Rules

Okay! Now let's write our validation rules. These are basically a LIST (or an array for the technically-literate), saying which form fields need to validated, in what way, and what errors should be displayed to the user if they're not filled in properly.

For the sake of example, we'll assume that all the fields in our sample form are required and we want to confirm that the email address they entered is valid. Here's what the PHP validation rules will look like:

$rules = array();
$rules[] = "required,subject,Please select a subject.";
$rules[] = "required,fullname,Please enter your name.";
$rules[] = "required,email,Please enter your email address.";
$rules[] = "valid_email,email,Please enter a valid email address.";
$rules[] = "required,comments,Please enter your comments.";

What we're doing here is creating a list of validation rules ([b]$rules[/b]), each of which contains (a) the validation rule itself, listed on an earlier page, (b) the name attribute of the form field that we're validating and (c) the error message that will be displayed to the user if the field is entered incorrectly.

Each component to the rule is separated by commas. Note: your error message cannot contain commas. This is currently a limitation of the script.