function isDateInPeriod(fromStr,toStr) {
         if(fromStr != "" && toStr != ""){
  var fromDtyr  = fromStr.substring(4,8);
var fromDtmth = fromStr.substring(2,4);
var fromDtday = fromStr.substring(0,2);

var toDtyr  = toStr.substring(4,8);
var toDtmth = toStr.substring(2,4);
var toDtday = toStr.substring(0,2);

var yrDiff = toDtyr - fromDtyr;

if(toDtmth < fromDtmth || (toDtmth==fromDtmth && toDtday < fromDtday)) {
  if(yrDiff != 0){
     yrDiff=yrDiff-1;
  }
}
if(yrDiff >= 2) {
  var errorMsg='<bean:message key="error.reg.maintainPAB.enquirePAB.invalidRegDtPeriod"/>';   
  alert(errorMsg);
  return false;
}
}
        return true;
}