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";
   
     }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();