Generador passwords Javascript


<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Generar password</title>

<script language="Javascript" type="text/JavaScript">
function generarPassword(form) {
    var strCaracteresPermitidos = 'a,b,c,d,e,f,g,h,i,j,k,m,n,p,q,r,s,t,u,v,w,x,y,z,1,2,3,4,5,6,7,8,9';
    var strArrayCaracteres = new Array(34);
    strArrayCaracteres = strCaracteresPermitidos.split(',');
    var length = form.txtCampoLongitud.value, i = 0, j, tmpstr = "";
    do {
        var randscript = -1
        while (randscript < 1 || randscript > strArrayCaracteres.length || isNaN(randscript)) {
            randscript = parseInt(Math.random() * strArrayCaracteres.length)
        }
        j = randscript;
        tmpstr = tmpstr + strArrayCaracteres[j];
        i = i + 1;
    } while (i < length)
    form.txtCampoPassword.value = tmpstr;
}
</script>
</head>

<body>
<form method="post" >
        <input type="text" name="txtCampoPassword" size="20" class="txtTexto">
        &nbsp;&nbsp;
        <input name="button" type="button" class="btnSubir" onClick="generarPassword(this.form);" value="Generar">
        <br>
        Longitud password:
        <input type="text" name="txtCampoLongitud" size="4" value="8" class="txtTexto">
      </form>
</body>

</html>