function getWhichbrowser(serRoot) {

	
	//operating system and browser detection
	
	
	
	var OpSys;
	
	var Browser = navigator.appName;
	
	var version = versionNumber();
	
	var servlet_root = serRoot;
	
	// var servlet_root = "/test_dir";
	
	
		function versionNumber() {
	
	  	// return version number (e.g., 4.03)
	
	  	return parseFloat(navigator.appVersion)
	
		}
	
	
	
	  if((navigator.userAgent.indexOf('Win') != -1) &&
	
	  (navigator.userAgent.indexOf('95') != -1))
	
	    { var OpSys = "pc"; }
	
	  else if(navigator.userAgent.indexOf('Win') != -1)
	
	    { var OpSys = "pc"; }
	
	  else if(navigator.userAgent.indexOf('Mac') != -1)
	
	    { var OpSys = "mac"; }
	
	  else { var OpSys = "other"; }
	
	
	
	  // when using ns4 on PC, this script redirects 2 unixns.css instead of pcns.css
	
	
	
		
	
		if ((Browser  == "Netscape") && (OpSys == "mac") && (version >= 5))
	
		{
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "/css/macmozilla.css\">");
	
		}
		
		
		if ((Browser  == "Mozilla") && (OpSys == "mac") && (version >= 5))
	
		{
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "/css/macmozilla.css\">");
	
		}
	
		
	
		else if ((Browser  == "Netscape") && (OpSys == "pc") && (version >= 5))
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/pcmozilla.css\">");
	
		}
	
		
	
		else if ((Browser  == "Netscape") && (OpSys == "mac"))
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/macns.css\">");
	
		}
	
		
	
		else if ((Browser  == "Netscape") && (OpSys == "pc"))
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/pcns.css\">");
	
		}
	
		
	
		//  does not direct to macie.css
	
		
	
		else if ((Browser  == "Microsoft Internet Explorer") && (OpSys == "mac"))
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/macie.css\">");
	
		}
	
		
	
		else if ((Browser  == "Microsoft Internet Explorer") && (OpSys == "pc"))
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/pcie.css\">");
	
		}
	
		
	
		else if (Browser  == "Mozilla")
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/pcmozilla.css\">");
	
		}
	
		
	
		else
	
		{
	
		document.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"" + servlet_root + "css/macie.css\">");
	
		}
}