function checkDate(date){ 
        if(date == "") { 
                return true; 
        } 
        
        var r = date.match(/^(\d{1,4})(-|\/)(\d{1,2})\2(\d{1,2})$/); 
            
        if (r==null) { 
                return false;     
        } 
        else { 
                return true;     
        } 
}