I'm writing this code in Flash builder and I tested the file in flash, but nothing appears in the swf file. (no text in the screen show , i don't know why) Is there any missing property in the code? Also, when I create text or movie clip with flash tools on the stage and give it an instance name, flash builder doesn't seem to recognize it in the action script code.

package
{
    import flash.display.MovieClip;
    import flash.text.TextField;

    public class mark extends MovieClip
    {

        public function mark()
        {

            super();
            public var d:TextField=new TextField();

            d.text="Hello world";
            d.x=250;
            d.y=300;
            addChild(d);


        }
    }