Hello,
I am quiet new to flex and need some help in displaying the base64 encoded
images contained in an array in a horizontal scroll list.

Details:

I have an array which contains base64 encoded strings(images).I want to
display it in a horizontal scroll with some image highlighting that is when i
move the cursor on to the displayed images.

Can anyone help me in this regard.

You'll have to do something like this:

var decoder:Base64Decoder = new Base64Decoder();
decoder.decode(yourBase64StringHere);
var bytes:ByteArray = decoder.toByteArray();

var bmpData:BitmapData = new BitmapData();
bmpData.setPixels(dimensions, bytes); //Note dimensions is a rectangle that
specifies the dimensions of your bitmap. not sure how you'd figure that out.

var bitmap:Bitmap = new Bitmap(bmpData);

Now you have a bitmap that you can work with like any other DisplayObject.