function getQSValue(qsKey)
{
  var qrStr = window.location.search;
  var spQrStr = qrStr.substring(1);
  var arrQrStr = new Array();
  // splits each of pair
  var arr = spQrStr.split('&');

  for (var i=0;i<arr.length;i++)
  {
    // splits each of field-value pair
    var index = arr[i].indexOf('=');
    var key = arr[i].substring(0,index);
    var val = arr[i].substring(index+1);

    // saves each of field-value pair in an array variable
    arrQrStr[key] = val;
  }
  
  return arrQrStr[qsKey];
}