function Browser() {

  var ua, s, i;

  this.isIE    = false;  // Internet Explorer
  this.isOP    = false;  // Opera
  this.isNS    = false;  // Netscape
  this.version = null;

  ua = navigator.userAgent;

  s = "Opera";
  if ((i = ua.indexOf(s)) >= 0) {
    this.isOP = true;
    this.version = parseFloat(ua.substr(i + s.length));
    return;
  }

  s = "Netscape6/";
  if ((i = ua.indexOf(s)) >= 0) {
    this.isNS = true;
    this.version = parseFloat(ua.substr(i + s.length));
    return;
  }

  // Treat any other "Gecko" browser as Netscape 6.1.

  s = "Gecko";
  if ((i = ua.indexOf(s)) >= 0) {
    this.isNS = true;
    this.version = 6.1;
    return;
  }

  s = "MSIE";
  if ((i = ua.indexOf(s))) {
    this.isIE = true;
    this.version = parseFloat(ua.substr(i + s.length));
    return;
  }
}

var browser = new Browser();

function ShowDropDownMenu (event, prefix)
{
	var button;
	if (browser.isIE)
		button = window.event.srcElement;
	else
		button = event.currentTarget;
	button.blur(); // 讓物件失去焦點

	//if (button.onmouseover == null)
	if (document.getElementById(prefix + "_LeftPaneTable").style.display == "none")
	{
		//
		// set an cookie for future visits, set lifetime to one year
		//
		//ak//setCookie ("leftpane", "1", 311040000);
	
		document.getElementById(prefix + "_LeftPaneTable").style.display = "";
	}
	else
	{
		//
		// set an cookie for future visits, set lifetime to one year
		//
		//ak//setCookie ("leftpane", "0", 311040000);

		document.getElementById(prefix + "_LeftPaneTable").style.display = "none";
	}
}