if(navigator.appVersion.indexOf("Mac") != -1)
{
    if(navigator.userAgent.indexOf("Safari") != -1)
    {
        document.write("<link href=\"_css/SiteStyles_mac_safari.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
    }
    else if(navigator.userAgent.indexOf("Firefox") != -1)
    {
        document.write("<link href=\"_css/StyleSheet_mac_ff.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
    }
    else
    {
        document.write("<link href=\"_css/SiteStyles_mac_safari.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
    }
}
else if(navigator.userAgent.indexOf("MSIE 7") != -1)
{
    document.write("<link href=\"_css/StyleSheet_ie.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
}
else if(navigator.userAgent.indexOf("Firefox") != -1)
{
    document.write("<link href=\"_css/StyleSheet_ff.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
}
else if(navigator.userAgent.indexOf("Safari") != -1)
{
    document.write("<link href=\"_css/SiteStyles_mac_safari.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
}
/*    alert(navigator.userAgent.indexOf("Safari"));
else if(navigator.userAgent.indexOf("Opera") != -1)
{
    document.write("<link href=\"_css/SiteStyles_opera.css\" rel=\"stylesheet\" type=\"text/css\"></link>");
}
*/