// get the browser information

function getOsName( )

{

	var userOs      = "" ;

	var regexResult = "" ;

	var moreInfo    = true ;

	var usrAgent    = navigator.userAgent.toUpperCase( ) ;



	if ( usrAgent.indexOf("WIN") != -1 ) userOs = "Windows" ;

	if ( usrAgent.indexOf("MAC") != -1 ) userOs = "MacOS" ;

	if ( usrAgent.indexOf("X11") != -1 ) userOs = "UNIX" ;



	return userOs ;

}



function getBrowserName( )

{

	var userBrowser = "" ;

	var appName     = navigator.appName.toUpperCase( ) ;



	if ( appName.indexOf("NETSCAPE")  != -1 ) userBrowser = "Netscape" ;

	if ( appName.indexOf("MICROSOFT") != -1 ) userBrowser = "Explorer" ;



	return userBrowser ;

}



function getBrowserVersion( )

{

	var version    = "" ;

	var start      = 0  ;

	var end        = 0  ;

	var usrBrowser = getBrowserName( ) ;

	var usrAgent   = navigator.userAgent.toUpperCase( ) ;

	var appVersion = navigator.appVersion ;



	if ( usrBrowser == "Netscape" )

	{

		start   = appVersion.indexOf(" ",0) ;

		version = appVersion.substring(0,start) ;

	}

	if ( usrBrowser == "Explorer" )

	{

		start   = appVersion.indexOf("MSIE ",0) + 5 ;

		end     = appVersion.indexOf(";",start) ;

		version = appVersion.substring(start,end) ;

	}



	return version ;

}


function printStyleSheet( )
{
	var WIN_IE4_SRC = "/system/win_ie.css" ;
	var WIN_IE5_SRC = "/system/win_ie.css" ;
	var WIN_NN4_SRC = "/system/win_nn4.css" ;
	var WIN_NN6_SRC = "/system/win_ie.css" ;
	var WIN_OPERA_SRC = "/system/win_ie.css" ;

	var MAC_IE4_SRC = "/system/mac_ie.css" ;
	var MAC_IE5_SRC = "/system/mac_ie.css" ;
	var MAC_NN4_SRC = "/system/mac_nn4.css" ;
	var MAC_NN6_SRC = "/system/mac_nn.css" ;
	var MAC_OPERA_SRC = "/system/mac_nn.css" ;

	// put the browser information in variable
	var os      = getOsName( ) ;
	var browser = getBrowserName( ) ;
	var version = getBrowserVersion( ).charAt( 0 ) ;

	var cssSrc = null ;

	if ( os == "Windows" )
	{
		if ( browser == "Explorer" )
		{
			if ( version == 4 )
			{
				cssSrc = WIN_IE4_SRC ;
			}
			if ( version >= 5 )
			{
				cssSrc = WIN_IE5_SRC ;
			}
		}
		else if ( browser == "Netscape" )
		{
			if ( version == 4 )
			{
				cssSrc = WIN_NN4_SRC ;
			}
			if ( version >= 5 )
			{
				cssSrc = WIN_NN6_SRC ;
			}
		}
		else if ( browser == "OPERA" )
		{
			cssSrc = WIN_OPERA_SRC ;
		}
	}
	else if ( os == "MacOS" )
	{
		if ( browser == "Explorer" )
		{
			if ( version == 4 )
			{
				cssSrc = MAC_IE4_SRC ;
			}
			if ( version >= 5 )
			{
				cssSrc = MAC_IE5_SRC ;
			}
		}
		else if ( browser == "Netscape" )
		{
			if ( version == 4 )
			{
				cssSrc = MAC_NN4_SRC ;
			}
			if ( version >= 5 )
			{
				cssSrc = MAC_NN6_SRC ;
			}
		}
		else if ( browser == "OPERA" )
		{
			cssSrc = MAC_OPERA_SRC ;
		}
	}

	// output the stylesheet
	if ( cssSrc )
	{
		document.open( ) ;
		document.write( '<LINK REL="stylesheet" TYPE="text/css" HREF="' + cssSrc + '">' ) ;
		document.close( ) ;
	}
}


printStyleSheet( ) ;