Movieclip.beginFill doesnt seem to work

Hi im currently working on making and filling closed figures with straight lines.

A portion of my code is as such.


        name = "line"+number_line;
        mc0 = _root.createEmptyMovieClip(name, number_line);
        mc0.lineStyle(1, 0x1919B3, 100);
        number_line++;
        name = "line"+number_line;
        mc1 = _root.createEmptyMovieClip(name, number_line);
        mc0.moveTo(xArray[0], yArray[0]);
        mc1.moveTo(_root[state](xArray[0], yArray[0]).x, _root[state](xArray[0], yArray[0]).y);
        mc0.beginFill(x0ffffff, 100);
        for (var i = 0; i<arrayPos; i++) {
            if (xArray[i+1] != undefined || xArray[i+1] != null) {
                mc0.lineTo(xArray[i+1], yArray[i+1]);
                mc1.lineStyle(1, 0x12127D, 100);
                mc1.lineTo(_root[state](xArray[i+1], yArray[i+1]).x, _root[state](xArray[i+1], yArray[i+1]).y);
                number_line++;
            }
        }

xArray and yArray are the arrays that stores each line position and i am wonder why begin fill does nothing, please advise, thanks in adv!