function Password(arg_password, arg_spc_chars)
{
    var password = arg_password;
    var spc_chars = arg_spc_chars;
    this.lcase_count = 0;
    this.ucase_count = 0;
    this.num_count = 0;
    this.schar_count = 0;
    this.length = 0;
    this.strength = 0;
    this.runs_score = 0;
    this.verdict = '';

    // These numbers are just guesses on my part (and not
    // all that educated, either ;) Adjust accordingly.
    var verdict_conv = {'weak':2.7, 'medium':5.3, 'strong':15.0};

    // These are weighting factors.  I figure that including
    // numbers is a little better than including uppercase
    // because numbers probably are not vulnerable to
    // dictionary searches, and including special chars is
    // even better.  These factors provide yet another
    // dimension.  Again, there are only guesses.
    /*
    var flc = 1.0;  // lowercase factor
    var fuc = 1.0;  // uppercase factor
    var fnm = 1.3;  // number factor
    var fsc = 1.5;  // special char factor
*/
    var flc = 1.0;  // lowercase factor
    var fuc = 1.0;  // uppercase factor
    var fnm = 1.3;  // number factor
    var fsc = 1.5;  // special char factor
    
    this.getStrength = function()
    {
        if ((this.run_score = this.detectRuns()) <= 1)
        {
            return "Adjon meg jelszót";
        }

        var regex_sc = new RegExp('['+spc_chars+']', 'g');

        this.lcase_count = password.match(/[a-z]/g);
        this.lcase_count = (this.lcase_count) ? this.lcase_count.length : 0;
        this.ucase_count = password.match(/[A-Z]/g);
        this.ucase_count = (this.ucase_count) ? this.ucase_count.length : 0;
        this.num_count   = password.match(/[0-9]/g);
        this.num_count   = (this.num_count) ? this.num_count.length : 0;
        this.schar_count = password.match(regex_sc);
        this.schar_count = (this.schar_count) ? this.schar_count.length : 0;
        this.length = password.length;

        var avg = this.length / 4;

        // I'm dividing by (avg + 1) to linearize the strength a bit.
        // To get a result that ranges from 0 to 1, divide 
        // by Math.pow(avg + 1, 4)
        this.strength = ((this.lcase_count * flc + 1) * 
                         (this.ucase_count * fuc + 1) *
                         (this.num_count * fnm + 1) * 
                         (this.schar_count * fsc + 1)) / (avg + 1);

        if (this.strength > verdict_conv.strong)
            this.verdict = 'erős';
        else if (this.strength > verdict_conv.medium)
            this.verdict = 'közepes';
        else if (this.strength > verdict_conv.weak)
            this.verdict = 'gyenge';
        else
            this.verdict = 'nagyon gyenge';

        return this.verdict;
    }

    // This is basically an edge detector with a 'rectified' (or
    // absolute zero) result.  The difference of adjacent equivalent 
    // char values is zero.  The greater the difference, the higher
    // the result.  'aaaaa' sums to 0. 'abcde' sums to 1.  'acegi'
    // sums to 2, etc.  'aaazz', which has a sharp edge, sums to  
    // 6.25.  Any thing 1 or below is a run, and should be considered
    // weak.
    this.detectRuns = function()
    {
        var parts = password.split('');
        var ords = new Array();
        for (i in parts)
        {
            ords[i] = parts[i].charCodeAt(0);
        }

        var accum = 0;
        var lasti = ords.length-1

        for (var i=0; i < lasti; ++i)
        {
            accum += Math.abs(ords[i] - ords[i+1]);
        }

        return accum/lasti;
    }


    this.toString = function()
    {
        return 'lcase: '+this.lcase_count+
               ' -- ucase: '+this.ucase_count+
               ' -- nums: '+this.num_count+
               ' -- schar: '+this.schar_count+
               ' -- strength: '+this.strength+
               ' -- verdict: '+this.verdict;
    }
}

function checkPassStrenth( value, obj ){
    
    var special_chars = "~!@#$%&*";

    var pw = new Password(value, special_chars);
    var verdict = pw.getStrength();

    if(verdict=='nagyon gyenge') color='red';
    else if(verdict=='gyenge') color='red';
    else if(verdict=='közepes') color='orange';
    else if(verdict=='erős') color='green';
    
    if(obj!=null){
        obj.innerHTML="a jelszó ereje: "+verdict;
        obj.style.color=color;
    }
}