x100 Times Tables

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="utf-8">
        <title>x100 Times Tables</title>
		<style>
		div {
			text-align:center;
			}
		body {
	background-color: black;
}
        body,td,th {
	color: rgba(255,255,255,1);
}
        </style>
    </head>
<body>
		<div><h1>Press Any Key to Start</h1>
		  <textarea style="height: 500px;" id="out"></textarea>
	<h3>See your favorite number up to x100!</h3></div>
<script>
            var out = document.getElementById("out");
            var input = 0;
            window.addEventListener("keyup", function(e) {
                out.innerHTML = "";
                if (e.which == 82) {
                    input = Math.floor(Math.random() * 1000);
                } else {
                    input = prompt("What number?");
                }
                if (isNaN(input)) {
                    out.innerHTML = "Input must only consist of numbers.";
                } else if (input == "") {
                    out.innerHTML = "Input cannot be blank.";
                } else if (input == 0) {
                    out.innerHTML = "Anything Multiplied by ZERO is ZERO.";
				} else if (input == null) {
                    out.innerHTML = "Hitting Cancel won't do the trick. Please enter a value.";
                } else {
                    for (var i = 1; i <= 100; i++) {
                        out.innerHTML += input + " x ";
						if (i < 100) { out.innerHTML += " "; }
						if (i < 10) { out.innerHTML += " "; }
						out.innerHTML += i + " = ";
						if (input * i < 10000) { out.innerHTML += " "; }
						if (input * i < 1000) { out.innerHTML += " "; }
						if (input * i < 100) { out.innerHTML += " "; }
						if (input * i < 10) { out.innerHTML += " "; }
						out.innerHTML += (input * i) + "\n";
                    }
                }
            });
        </script>
</body>
</html>