Detect the intersection point of 2 lines

I have 2 (VisualBasic.PowerPacks)LineShapes on my form:

alt text http://lh4.ggpht.com/_1TPOP7DzY1E/S2cIJan7eHI/AAAAAAAADAw/qwA0jFHEbBM/s800/intersection.png

When I click on one of them, a specific context menu appears. The lines can be moved by the user. A context Menu is associated with a line. However, if the user clicks in the intersection point(if exists) I need to display an other menu, that will select one of intersection lines to perform an action.

Now, I wonder how to detect that 2 (or more) lines are intersected in the click point, because an other context-menu should appear in this case.

What I tried to do:

    private void shapeContainer1_MouseDown(object sender, MouseEventArgs e)
    {
        // right click only
        if (e.Button == MouseButtons.Right)
        {
            LineShape target = 
                (shapeContainer1.GetChildAtPoint(e.Location) as LineShape);

            if (target != null)
            {
                Console.WriteLine(new Point(target.X1, target.Y1));
            }

        }
    }

I suppose I have only LineShapes in the container. This told, the ShapeContainer will not raise a MouseDown event if any LineShape will be under the mouse.

But this code gives me only the mostTop line, but I want a list of others too.

    /// obtains a list of shapes from a click point
    private List<LineShape> GetLinesFromAPoint(Point p) 
    {
        List<LineShape> result = new List<LineShape>();
        Point pt = shapeContainer1.PointToScreen(p);

        foreach (Shape item in shapeContainer1.Shapes)
        {
            LineShape line = (item as LineShape);
            if (line != null && line.HitTest(pt.X, pt.Y))
            {
                result.Add(line);                    
            }
        }
        return result;
    }

    private void shapeContainer1_MouseDown(object sender, MouseEventArgs e)
    {
        // right click only
        if (e.Button == MouseButtons.Right)
        {
            List<LineShape> shapesList = GetLinesFromAPoint(e.Location);
            Console.WriteLine(DateTime.Now);
            Console.WriteLine("At this point {0} there are {1} lines.", 
                e.Location, shapesList.Count);
        }
    }