phpfiddle/fiddle_084335.php

## fiddle_084335.php
<?php
/**
Finding an exact match in a text file using PHP AJAX jQuery form
http://stackoverflow.com/questions/15121403/finding-an-exact-match-in-a-text-file-using-php-ajax-jquery-form

*/

if(isset($_POST["email"])){
    $email = $_POST['email'];
    $emails = <<<emails
Bobby Brown bobby@somewhere.com
Guy Slim guy@somewhere.com
Slim Jim slim@somewhere.com
emails;
    if (strpos($email,'@')) {
        $match = preg_match("/\b{$email}\b/i", $emails );
        if ( $match) {
            echo "Found!";
        }
        else {
            echo "Sorry, not found";
        }
    }
    else {
            echo "Sorry, not found";
    }
}else {
?>
<html>
<body>
    <form>
        Email address:<input type="text" name="usr" id="usr" />
        <input type="submit" id="submit"  name="submit" value="Submit"></form>
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.3/jquery.min.js"></script>
         <script type="text/javascript">
    var $url =  '<?php echo $_SERVER['PHP_SELF']; ?>';
    $('#submit').click(function(e){
        e.preventDefault();
        var id = 3;
        $.ajax({
            url: '<?php echo $_SERVER['PHP_SELF']; ?>',
            type: 'POST',
            data: "email="+ usr.value,
            success: function(msg){
                jQuery('body').append(msg);
            },
            error: function(){
                alert("Error");
            }
        });
    });
</script>

    </body>
</html>
<?php
      }
?>
	<?php
	/**
	Finding an exact match in a text file using PHP AJAX jQuery form
	http://stackoverflow.com/questions/15121403/finding-an-exact-match-in-a-text-file-using-php-ajax-jquery-form

	*/

	if(isset($_POST["email"])){
	$email = $_POST['email'];
	$emails = <<<emails
	Bobby Brown bobby@somewhere.com
	Guy Slim guy@somewhere.com
	Slim Jim slim@somewhere.com
	emails;
	if (strpos($email,'@')) {
	$match = preg_match("/\b{$email}\b/i", $emails );
	if ( $match) {
	echo "Found!";
	}
	else {
	echo "Sorry, not found";
	}
	}
	else {
	echo "Sorry, not found";
	}
	}else {
	?>
	<html>
	<body>
	<form>
	Email address:<input type="text" name="usr" id="usr" />
	<input type="submit" id="submit" name="submit" value="Submit"></form>
	<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.3/jquery.min.js"></script>
	<script type="text/javascript">
	var $url = '<?php echo $_SERVER['PHP_SELF']; ?>';
	$('#submit').click(function(e){
	e.preventDefault();
	var id = 3;
	$.ajax({
	url: '<?php echo $_SERVER['PHP_SELF']; ?>',
	type: 'POST',
	data: "email="+ usr.value,
	success: function(msg){
	jQuery('body').append(msg);
	},
	error: function(){
	alert("Error");
	}
	});
	});
	</script>

	</body>
	</html>
	<?php
	}
	?>