javascript:(function(){var getRandomPass=function(d){var chars='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';var rez='';var len=d>=3?d:3;while(rez.length<len){rez+=chars.charAt(Math.floor(Math.random()*chars.length))}return/^(?=.*\d)(?=.*[a-z])(?=.*[A-Z]).+$/.test(rez)?rez:arguments.callee(len)};var findPassEle=function(p){var c,s='',r=false,f=document.getElementsByTagName('form');for(var i=0;i<f.length;i++){c=f[i].elements;for(var j=0,e;e=c[j];j++){if(e.type=='password'){r=true;if(p){e.value=p;e.focus()}else if(e.value)s+='\n\n'+e.value}}};return r?s:null};var s=findPassEle();if(s){alert('%D0%9D%D0%B0 %D1%8D%D1%82%D0%BE%D0%B9 %D1%81%D1%82%D1%80%D0%B0%D0%BD%D0%B8%D1%86%D0%B5 %D1%83%D0%B6%D0%B5 %D0%B8%D0%BC%D0%B5%D0%B5%D1%82%D1%81%D1%8F %D0%BF%D0%B0%D1%80%D0%BE%D0%BB%D1%8C:'+s)}else{findPassEle(prompt('%D0%9F%D0%B0%D1%80%D0%BE%D0%BB%D1%8C %D1%81%D0%B3%D0%B5%D0%BD%D0%B5%D1%80%D0%B8%D1%80%D0%BE%D0%B2%D0%B0%D0%BD'+(s==null?':':'. %D0%92%D1%81%D1%82%D0%B0%D0%B2%D0%B8%D1%82%D1%8C?'),getRandomPass(12)))}})()

<form name="pass_form">Пароль: <input name="pass" size="25" type="text" value="">
<input type="button" value="Сгенерировать" onClick="gen_pass()"></form>

<script type="text/javascript">
chr = new Array('A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z',0,1,2,3,4,5,6,7,8,9);

function rnd(x,y,z) {
var num;
do {
num = parseInt(Math.random()*z);
if (num >= x && num <= y) break;
} while (true);
return(num);
}

function gen_pass() {
var pass = '';
for (var i = 0; i < 20; i++) pass += chr[rnd(0,61,100)];
document.pass_form.pass.value = pass;
}
</script>