Random password generator bookmarklet

genpassword.js

javascript:void(function() {
	var chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
	var password = "";
	for (var i = 0, length = 64; i < length; ++i) {
		password += chars[~~(Math.random() * chars.length)];
	}
	var input = document.getElementById("f773da90-5044-11e3-8f96-0800200c9a66") || document.createElement("input");
	if (!input.id) {
		input.id = "f773da90-5044-11e3-8f96-0800200c9a66";
		input.setAttribute("style", "background:deeppink;border:2px solid #000;border-radius:.25em;box-shadow:0 0 1em .25em rgba(0,0,0,.5);color:#fff;position:fixed;top:1em;left:1em;font:16px/1 Helvetica,sans-serif;padding:.5em;z-index:9999;opacity:1;transition:opacity .5s;");
		input.addEventListener("copy", function() {
			if (typeof document.body.style["transition"] === "string") {
				input.style["opacity"] = 0;
				input.addEventListener("transitionend", function() {
					document.body.removeChild(input);
				});
			}
			else {
				setTimeout(function() {
					document.body.removeChild(input);
				}, 500);
			}
		});
		document.body.appendChild(input);
	}
	input.value = password;
	input.select();
})();