How do I make writing/drawing happen?

My goal is to have the user write on the screen like a whiteboard.

Currently I'm just creating a dot when in touch, and this works, until the user moves too fast, then you get spaces in between.

So, I tried creating a line to link the dots together (using setting angles and distance), and that only looks good if the line is very thin (and I'm going for a thick line).

Any ideas?

You can try this tutorial: scirra.com/tutorials/1207/how-to-make-a-drawing-canvas