function browserCheck(){
    var browser = navigator.appName;
    var version = navigator.appVersion;
    if ( browser == "Microsoft Internet Explorer" && version.indexOf( "MSIE 5.0" ) > -1 ) {
        return B_MSIE;
    } else if ( browser == "Netscape" && parseInt( version.substring( 0,1 ) ) > "4" ) {
        return B_MOZILLA;
    } else if ( browser == "Netscape" && parseInt( version.substring( 0,1 ) ) <= "4" ) {
          return B_NS4;
    } else {
        return B_OTHER;
    }
}

function platformCheck(){
    if ( navigator.platform == "Win32" ) {
        return P_WIN32;
    } else if ( navigator.platform.substring( 0, 3 ) == "Mac" ) {
        return P_MAC;
    } else if ( navigator.platform.substring( 0, 5 ) == "Linux" ) {
        return P_LINUX;
    } else {
        return P_OTHER;
    }
}