hdragomir/prime-checker.html

## prime-checker.html
<html>

    <head>
        <title>prime number checker</title>

        <style>

            body, input{
                font-family: Georgia, serif;
                background-color: white;
            }

            form{
                text-align: center;
                width: 33%;
                margin: 50px auto;
            }

            output{
                display: block;
                text-align: center;
            }

            .false{
                color: red;
            }

            .true{
                color: green;
            }

            input{
                line-height: 4em;
                height: 4em;
                border: 0;
                text-align: center;
                font-size: 2em;
            }

        </style>

        <script>

            var input, output, re = /^1?$|^(11+?)\1+$/;


            document.addEventListener('DOMContentLoaded', function(){
                input = document.querySelector('input[type=text]');
                output = document.querySelector('output');
                input.addEventListener('keyup', function(){
                    input.className = output.className = output.value = isPrime(input.value);
                }, false);
                input.focus();
                document.querySelector('form').addEventListener('submit', function(ev){
                    ev.preventDefault();
                    return false;
                }, false);
            }, false);


            function isPrime(number){
                return !re.test((function(i){
                    var pad = '';
                    while(i--) pad += '1';
                    return pad;
                })(number));
            }

        </script>

    </head>

    <body>
        <form action="" method="get">
            <input type="text" />
            <output />
        </form>
    </body>
    <!-- gist by hdragomir (http://hdragomir.com/), regex by avinash (http://www.noulakaz.net/weblog/2007/03/18/a-regular-expression-to-check-for-prime-numbers/) -->
</html>
	<html>

	<head>
	<title>prime number checker</title>

	<style>

	body, input{
	font-family: Georgia, serif;
	background-color: white;
	}

	form{
	text-align: center;
	width: 33%;
	margin: 50px auto;
	}

	output{
	display: block;
	text-align: center;
	}

	.false{
	color: red;
	}

	.true{
	color: green;
	}

	input{
	line-height: 4em;
	height: 4em;
	border: 0;
	text-align: center;
	font-size: 2em;
	}

	</style>

	<script>

	var input, output, re = /^1?$\|^(11+?)\1+$/;


	document.addEventListener('DOMContentLoaded', function(){
	input = document.querySelector('input[type=text]');
	output = document.querySelector('output');
	input.addEventListener('keyup', function(){
	input.className = output.className = output.value = isPrime(input.value);
	}, false);
	input.focus();
	document.querySelector('form').addEventListener('submit', function(ev){
	ev.preventDefault();
	return false;
	}, false);
	}, false);


	function isPrime(number){
	return !re.test((function(i){
	var pad = '';
	while(i--) pad += '1';
	return pad;
	})(number));
	}

	</script>

	</head>

	<body>
	<form action="" method="get">
	<input type="text" />
	<output />
	</form>
	</body>
	<!-- gist by hdragomir (http://hdragomir.com/), regex by avinash (http://www.noulakaz.net/weblog/2007/03/18/a-regular-expression-to-check-for-prime-numbers/) -->
	</html>