You can input two vectors (shown in blue relative to the white axes) on the right hand side by entering one component at a time. When you click on "calculate the cross product" button the coordinates of the resulting normal vector is shown below. When you click the "display vector" button the new vector perpendicular to the old vectors should be drawn in green - unfortunately you may need to change the camera position to get the image to be updated - sorry:(
To get a much better feel for the cross product try this applet at the University of Syracuse, which allows you to vary the two vectors a and b and see what happens to their cross product in real time.