AS3 – Unable to resize Image width and height

I have a problem that when I load image it doesn’t resize to the value I set in my button, so the button resize itself to fill the image, i think!

And when I see value like 200,200 the resulted image is like 3-4 times bigger than 100,100

public function MyButton()
{// this is ctor
   ImageLoader = new Loader();
   addChild(ImageContainer);
}
public function SetWidthAndHeight(newWidth: Number, newHeight: Number): void
{
    width = newWidth;
    height = newHeight;
    //ImageContainer is a MovieClip inside the button
    ImageContainer.height = newHeight;
    ImageContainer.width = newWidth;
}
public function LoadImage(address: String): void
{    
   
    ImageLoader.load(new URLRequest(address));
}

I set the value like

 var g_newButton = new MyButton();
 g_newButton.ImageLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, OnCompleteHandler);**strong text**

 g_newButton.SetWidthAndHeight(100,100);
 g_newButton.LoadImage("myImage.jpg");
function OnCompleteHandler(loadEvent: Event) 
{   
     //g_newButton.ImageLoader.content is always null
    trace("button width " +g_newButton.width);
    trace("button height " +g_newButton.height);
    g_newButton.ImageContainer.addChild(loadEvent.currentTarget.content);
    addChild(g_newButton);
}

when I run, these are the values I get

button width 750

button height 385.55

so Why i am not getting

button width 100

button height 100
what should i do to make the image resize to fill a button or to have the same size of the button