function isDate(day, month, year) { 

    try  {
    
       if ((day < 1) || (day < 1 || day > 30) && (month == 4 || month == 6 || month == 9 || month == 11) || day > 31) { 
       
           return false; 
       } 
    
       if (month < 1 || month > 12) { 
       
           return false;
       } 
    
       if(year == '' || year < 1900)   {
       
           return false;
       }
           
       if (month == 2 && (day < 1 || day > 29 || (day > 28 && (parseInt(year / 4) != year / 4)))) { 
       
           return false;
       } 
   }
   catch(Exception) {
   
        return false;
   }
   
   return true; 
}

function isAgeValid(validAge,year,month,day) {

	var byear = parseInt(year);                // year entered 
	var bmonth = parseInt(month);              // month entered
	var bday = parseInt(day);                  // day entered
	var today = new Date();                    // full date of today
	var currYear = today.getFullYear();        // year of today
	var currMonth = today.getMonth();          // month of today (0-11)
	var currDay = today.getDate();             // day of today (1-31)

    // add 1 to curr month since it is zero based
    currMonth += 1;               
   
    // # years diff between date entered and today
    var yearsDiff = currYear - byear;     
  
    // debug info ...
    //alert (byear + " " + currYear + "\n" + bmonth + " " + currMonth + "\n" + bday + " " + currDay);
  
    if (yearsDiff > validAge) {           // if yearsdiff > the valid age, let it pass
    
       //alert ("ok you old fart");
        return true; 
        
    } else if (yearsDiff < validAge) {    // yearsdiff < validage, fail
    
    	return false; 
    	
    } else {                              // same year as threshold; use month/day to determine
    
    	if (bmonth < currMonth) {         // had birthday in prior month this year - pass
    	
        	return true; 
        	
        } else if (bmonth > currMonth) {  // haven't had your birthday yet this year - fail
        
        	return  false; 
        	
        } else {                          // birthday is this month       
        
        	if (bday <= currDay) {        // birthday earlier this month or today
        	
            	return true;  
            	
            } else {                      // birthday later this month - fail
            
            	return false;   
            } 
        }  
        
      	return false;
    } 
    
    return  false; 
}