Varien.DateElement.prototype.validate = function() {
        var error = false, day = parseInt(this.day.value, 10) || 0, month = parseInt(this.month.value, 10) || 0, year = parseInt(this.year.value, 10) || 0;
    if (!day && !month && !year) {
            if (this.required) {
                error = 'This date is a required value.';
            } else {
                this.full.value = '';
            }
        } else if (!day || !month || !year) {
            error = 'Please enter a valid full date.';
        } else {
            var date = new Date, countDaysInMonth = 0, errorType = null;
            date.setYear(year);date.setMonth(month-1);date.setDate(32);
            countDaysInMonth = 32 - date.getDate();
            if(!countDaysInMonth || countDaysInMonth>31) countDaysInMonth = 31;

            if (day<1 || day>countDaysInMonth) {
                errorType = 'day';
                error = 'Please enter a valid day (1-%d).';
            } else if (month<1 || month>12) {
                errorType = 'month';
                error = 'Please enter a valid month (1-12).';
            }else if(this.year.value.length != 4)
            {
            	errorType = 'year';
               error = 'Please enter the year with 4 numbers.';
            } else {
                if(day % 10 == day) this.day.value = '0'+day;
                if(month % 10 == month) this.month.value = '0'+month;
                this.full.value = this.format.replace(/%[mb]/i, this.month.value).replace(/%[de]/i, this.day.value).replace(/%y/i, this.year.value);
                var testFull = this.month.value + '/' + this.day.value + '/'+ this.year.value;
                var test = new Date(testFull);
                if (isNaN(test)) {
                    error = 'Please enter a valid date.';
                } else {
                    this.setFullDate(test);
                }
            }
            var valueError = false;
            if (!error && !this.validateData()){//(year<1900 || year>curyear) {
                errorType = this.validateDataErrorType;//'year';
                valueError = this.validateDataErrorText;//'Please enter a valid year (1900-%d).';
                error = valueError;
            }
        }

        if (error !== false) {
            try {
                error = Translator.translate(error);
            }
            catch (e) {}
            if (!valueError) {
                this.advice.innerHTML = error.replace('%d', countDaysInMonth);
            } else {
                this.advice.innerHTML = this.errorTextModifier(error);
            }
            this.advice.show();
            return false;
        }

        // fixing elements class
        this.day.removeClassName('validation-failed');
        this.month.removeClassName('validation-failed');
        this.year.removeClassName('validation-failed');

        this.advice.hide();
        return true;
 };