Why does ADODB.STREAM not work in Internet Explorer 9?

Why doesn't this code work in Internet Explorer 9?

funct开发者_如何学JAVAion GetFile(FileName) {
    var Contents1=null;
    var Stream;
    Stream = new ActiveXObject("ADODB.Stream")
    Stream.Type = 1 //Binary
    Stream.Open()
    Stream.LoadFromFile(FileName)
    Contents1 = Stream.Read()
    FileSize = Stream.Size
    Stream.Close()
    return Contents1;
}

 Contents1 = Stream.Read(-1); //-1 adReadAll