Whats a good way to teach a scared girl how to ride a bike?

[mjoy2685]

My daughter wants her training wheels off but last summer when we tried to take them off she got to scared and dad and I dont know how to really teach her. She is very cautious and when she gets scared she stops and wants to give up. We dont really let her give up but after several lessons we decided that maybe it was too early ( she was 5 then) and to try again this summer. Does any one have tips or pointers on how to teach her this.
Also we are working on roller skating but this is another thing that she worries about falling, she wants to roller skate but as soon as she gets wobbley she starts crying and says she doesnt want to do it anymore. How do we help her build up her confidence and get over her fears?