Can't control a Vibration Motor

Hello Techs!

I'm a newbie of electronic and arduino.
Now I tried to control a vibration moter by arduino. I just used some High Low code but the motor goes fast and slow.
Do anybody know why that happeneds? Is that I need to connect some other components with it?

Cheers,
Gindo

I just used some High Low code but the motor goes fast and slow.

"Fast" and "stopped" I can believe, followed shortly by smoke.

What is your motor, how much current does it draw, and where is your code?

I just transformed a toy motor to a vibration motor. I followed the current and code in this web: Arduino 12: Transistors | Quarkstream It should be right because it's quite simple.
Then I tried replacing by a coin vibration motor, it worked properly... what's wrong?...

That circuit is missing a resistor to the base and missing a flyback diode.
That circuit is very wrong. Perhaps the transistor is already blown and the Arduino could be damaged.

Use this, http://arduino.cc/forum/index.php/topic,109608.msg823121.html#msg823121
The relay can be a motor.