/**
* Help evaluate day according to month selected 
*@author gep@osiacat.ru
*
*/
$.extend({
	
	removeDaysOptions: function(birth_day){
        	birth_day.children("option[value=29]").remove();
        	birth_day.children("option[value=30]").remove();
        	birth_day.children("option[value=31]").remove();
    },
    
    removeDayOptions: function(birth_day, day){
            birth_day.children("option[value="+day+"]").remove();
    },
        
        
    editDayAccordingToMonth: function(birth_month, birth_day, birth_year){
        	var option29 = $('<option value="29">29</option>');
        	var option30 = $('<option value="30">30</option>');
        	var option31 = $('<option value="31">31</option>');
            var currDay = parseInt(birth_day.children("option:selected").val());
            
        	switch (parseInt(birth_month.children("option:selected").val())){
           		case 1: var day_option = 1; break;
           		case 2: var day_option = 3; break;
           		case 3: var day_option = 1; break;
           		case 4: var day_option = 2; break;
           		case 5: var day_option = 1; break;
           		case 6: var day_option = 2; break;
           		case 7: var day_option = 1; break;
           		case 8: var day_option = 1; break;
           		case 9: var day_option = 2; break;
           		case 10: var day_option = 1; break;
           		case 11: var day_option = 2; break;
           		case 12: var day_option = 1; break;
           }
           $.removeDaysOptions(birth_day);
           switch (day_option){
           		case 1:
           			birth_day.append(option29);
	           		birth_day.append(option30);
	           		birth_day.append(option31);
           		break;
           		case 2:
           			birth_day.append(option29);
	           		birth_day.append(option30);
           		break;
           		case 3:
           			if (!(parseInt(birth_year.children("option:selected").val()) % 4)){
           				birth_day.append(option29);
           			}
           		break;
           }
           birth_day.val(currDay);
           
        }
});