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; 
            } 
            

    } 


} 

// Trap Backspace(8) and Enter(13) esckey()l- 
// Except bksp on text/textareas, enter on textarea/submit

  if (typeof window.event != 'undefined') // IE
   document.onkeydown = function() // IE
    {
    var t=event.srcElement.type;
    var kc=event.keyCode;
    
      return ((kc != 8 && kc != 13 && kc != 27) || ( t == 'select-one' &&  kc == 13 ) || ( t == 'text' &&  kc != 13 && kc != 27) ||
             (t == 'textarea' && kc != 27) || ( t == 'submit' &&  kc == 13) || ( (t != 'text' && t != 'textarea') && kc == 27))
    }
else
  document.onkeypress = function(e)  // FireFox/Others 
    {
    var t=e.target.type;
    var kc=e.keyCode;
    
    if ((kc != 8 && kc != 13 && kc != 27 )   || ( t == 'select-one' &&  kc == 13 ) || ( t == 'text' &&  kc != 13  && kc != 27) ||
        (t == 'textarea' && kc != 27) || ( t == 'submit' &&  kc == 13) || ( (t != 'text' && t != 'textarea') && kc == 27))
        return true
    else {
        alert('Sorry Backspace/Enter is not allowed here'); // Demo code
        return false
    }
   }

//history.forward();