Minor UI suggestions

[finetjul]

Here are some suggestions to polish the example:

• 1: remove empty space
• 2: remove/hide non functioning button
• 3: remove/hide non functioning button
• 4: hide useless overflow scroll
• 5: correctly initialize height
• 6: Rename "Get Number Of Cells" into "Print number of cells"

[hem0805]

Are the reset buttons working ?