LogMessage(GetJScriptVersionInfo());

function GetJScriptVersionInfo()
{
    var s;
    s = ""; // Build string with necessary info.
    s += ScriptEngine() + " Version: ";
    s += ScriptEngineMajorVersion() + ".";
    s += ScriptEngineMinorVersion() + ".";
    s += ScriptEngineBuildVersion();
    return(s);
}

On Linux:

// INFO : JScript Engine Version: 5.1.4411

On Windows:

// INFO : JScript Version: 5.8.16762