how to adjust brightness etc . in web page with vlc activex

[chiao]

I have streamed mpg file in web page embedded with vlc0.8.5 activex;
Now I wanna adjust image effective realtime,such as brightness,contrast,hue,saturation etc.
But I still face to failure after many efforts to use vlc activex method : setVariable() .
well , the follow javascript can adjust image effective:

var options = new Array(":vout-filter=adjust", ":hue=120"); document.vlc.addTarget(TargetUrl, options, 4+8, -666);


but not what I need!
I used setVariable() method as follows:
var hstr="hue";
var hvalue=120;
document.vlc.setVariable(hstr,hvalue);

or
var hstr="hue";
var hvalue;
document.vlc.getVariable(hstr,hvalue);
document.vlc.setVariable(hstr,hvalue);
document.write("ok");

but nothing to happen

who can help me ? thanks in advance!