<?php # Script 2.4 - form processing with error handling
//check if form has been submitted
$sent = (isset($_REQUEST['submit']))?$_REQUEST['submit']:null;
if($sent) {
	// Validate the name:
	if (!empty($_REQUEST['name'])) {
		$name = $_REQUEST['name'];
	} else {
		$name = NULL;
		echo '<p class="error">You forgot to enter your name!</p>';
	}

	// Validate the email:
	if (!empty($_REQUEST['email'])) {
		$email = $_REQUEST['email'];
	} else {
		$email = NULL;
		echo '<p class="error">You forgot to enter your email address!</p>';
	}

	// Validate the comments:
	if (!empty($_REQUEST['comments'])) {
		$comments = $_REQUEST['comments'];
	} else {
		$comments = NULL;
		echo '<p class="error">You forgot to enter your comments!</p>';
	}

	// Validate the gender:
	if (isset($_REQUEST['gender'])) {

		$gender = $_REQUEST['gender'];
		
		if ($gender == 'M') {
			$greeting = '<p><b>Good day, Sir!</b></p>';
		} elseif ($gender == 'F') {
			$greeting = '<p><b>Good day, Madam!</b></p>';
		} else { // Unacceptable value.
			$gender = NULL;
			echo '<p class="error">Gender should be either "M" or "F"!</p>';
		}
		
	} else { // $_REQUEST['gender'] is not set.
		$gender = NULL;
		echo '<p class="error">You forgot to select your gender!</p>';
	}

	// If everything is OK, print the message:
	if ($name && $email && $gender && $comments) {

		echo "<p>Thank you, <b>$name</b>, for the following comments:<br />
		<tt>$comments</tt></p>
		<p>We will reply to you at <i>$email</i>.</p>\n";
		
		echo $greeting;
		
	} else { // Missing form value.
		echo '<p class="error">Please go back and fill out the form again.</p>';
		echo '<input type="button" value="Back" onclick="window.history.back();">';
	}
} else { ?>
	<!-- Script 2.1 - the form -->
	<form action='#' method="post">

		<fieldset><legend>Enter your information in the form below:</legend>
		
		<p><label>Name: <input type="text" name="name" size="20" maxlength="40" /></label></p>
		
		<p><label>Email Address: <input type="text" name="email" size="40" maxlength="60" /></label></p>
		
		<p><label for="gender">Gender: </label><input type="radio" name="gender" value="M" /> Male <input type="radio" name="gender" value="F" /> Female</p>
		
		<p><label>Age:
		<select name="age">
			<option value="0-29">Under 30</option>
			<option value="30-60">Between 30 and 60</option>
			<option value="60+">Over 60</option>
		</select></label></p>
		
		<p><label>Comments: <textarea name="comments" rows="3" cols="40"></textarea></label></p>
		
		</fieldset>
		
		<p align="center"><input type="submit" name="submit" value="Submit My Information" /></p>

	</form>
<?php } ?>