function isDate(dateStr) {

    var datePat = /^(\d{1,2})(\/|-)(\d{1,2})(\/|-)(\d{4})$/;
    var matchArray = dateStr.match(datePat); // is the format ok?
    if (matchArray == null) {return false;}
    day = matchArray[1]; // p@rse date into variables
    month = matchArray[3];
    year = matchArray[5];
    if (month < 1 || month > 12) {return false;}
    if (day < 1 || day > 31) {return false;}
    if ((month==4 || month==6 || month==9 || month==11) && day==31) {return false;}
    if (month == 2) { // check for february 29th
        var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
        if (day > 29 || (day==29 && !isleap)) {return false;}
    }
    return true; // date is valid
}


function CheckDate_OnChange(ddlDayname,ddlMnthname,ddlYearname,divname)
{ 
   var d=document.getElementById(ddlDayname).value;
   var m=document.getElementById(ddlMnthname).value;
   var y=document.getElementById(ddlYearname).value;
    
        if (!isDate(d + '/' + m + '/' + y))
        { 
          document.getElementById(divname).style.display ="inline";
          return(false)
        }else
        {
          document.getElementById(divname).style.display ="none";
          return(true);
        }
}

//function click(e) { 
//    var message="?????? The right-click has been disabled"; 
//    if (document.all) { 
//            if (event.button==2||event.button==3) { 
//                        alert(message); 
//                        return false; 
//                        } 
//     } 
//    if (document.layers) { 
//            if (e.which == 3) { 
//                    alert(message); 
//                    return false; 
//            } 
//            

//    } 


//} 

//history.forward();