(function(undefined) {
    /* local var and method */
    
    /* object prototype */
    
    /* public method and attribute */
    
    /**
    * check string format
    */
    $$.check = {};
    
    $$.check.email = function(email) {
    
        var at="@";
        var dot=".";
        var lat=email.indexOf(at);
        var lstr=email.length;
        var ldot=email.indexOf(dot);
        if (email.indexOf(at)==-1) {
            return false;
        }
        if (email.indexOf(at)==-1 || email.indexOf(at)==0 || email.indexOf(at)==lstr) {
            return false;
        }
        if (email.indexOf(dot)==-1 || email.indexOf(dot)==0 || email.indexOf(dot)==lstr) {
            return false;
        }
        if (email.indexOf(at,(lat+1))!=-1) {
            return false;
        }
        if (email.substring(lat-1,lat)==dot || email.substring(lat+1,lat+2)==dot) {
            return false;
        }
        if (email.indexOf(dot,(lat+2))==-1){
            return false;
        }
        if (email.indexOf(" ")!=-1) {
            return false;
        }
        // check by regular expression
        emailreg = '^[a-z0-9_\.-]+@[a-z0-9_\.-]+\.[a-z]{2,6}$';
        var re = new RegExp(emailreg, 'i');
        return re.test(email);
        
    }
    
    $$.check.password = function(password) {
        var error = 0;
        // Validate lowercase letters
        var lowerCaseLetters = /[a-z]/g;
        if(password.match(lowerCaseLetters)) {
        } else {
            error++;
        }
        
        // Validate capital letters
        var upperCaseLetters = /[A-Z]/g;
        if(password.match(upperCaseLetters)) {  
        } else {
            error++;
        }

        // Validate numbers
        var numbers = /[0-9]/g;
        if(password.match(numbers)) {  
        } else {
            error++;
        }
        
        // Validate '_@*^$'
        var special = /[_@*^$]/g;
        if(password.match(special)) {  
        } else {
            error++;
        }

        // Validate length
        if(password.length >= 8) {
        } else {
            error++;
        }


        return error == 0;
    }
  
  
})();