[Skipp]

<script type="text/javascript">
	function gen(n){
		var arg = new Array();
		for(var i=0; i<n;i++) arg.push(rand(48,58), rand(65,91), rand(97,123))
		for(var j, x, y = arg.length; y; j = parseInt(Math.random() * y), x = arg[--y], arg[y] = arg[j], arg[j] = x);
		return String.fromCharCode.apply(this, arg);
	}
	function rand(min, max){
		return Math.floor(Math.random() * (max - min) + min);
	}
</script>
<input id="pass" type="text" />
<input type="button" value="Генерировать 12" onclick="document.getElementById('pass').value = gen(4)" />
<input type="button" value="Генерировать 10" onclick="document.getElementById('pass').value = gen(4).substr(1, 10)" />
<input type="button" value="Генерировать 8" onclick="document.getElementById('pass').value = gen(3).substr(1, 8)" />