There is times when your mouse will do something great for you. This is one of that rare times. Your mouse can control your Dock easily.

1. Click and Hold on the grid border of your dock
   

   

2. Move your mouse up will increase your dock size. Move your mouse down will decrease your dock size
3. Still holding your dock grid border, and pressing will do similar to number 2, except the increasing and decreasing ratio is fixed.
4. Release your key and replace with holding key and move your mouse to left-most, bottom or right-most of your screen will change the position of your dock
5. Those actions come in handy, right?