this program draws the mandelbrot set using the pixel by pixel iteration method
-a suitable graphics window is set and the steps dx and dy are calculated
-two for-loops go through all the pixels of the screen
-the starting point z and c of the recursive sequence z:=z^(2)+care set.
-the first 25 terms are calculated until abs(z)>2, in this case the startingpoint is drawn using
the color to varies between red and blue. Using k:=25 ends the for loop.
-the program then switches to the next pixel
- this program is too slow for a handheld, it works fine on the sofware version