Servo to sweep with toggle switch

hello. i am new to arduino and i want to control a servo with a toggle switch.
when the switch is in one state say LOW then the servo will be at 0*
and when the switch is HIGH then the servo will sweep over to 180* in one fluid motion.
and when the switch is flipped back it will return to 0*

any suggestions would be great. i have found some code about sweeping at each degree and also some about the position of a pot but i don't know how to take those examples and use them to do what i want.

thanks everyone.

Very simple servo test code.

//zoomkat servo button test 7-30-2011

#include <Servo.h>
int button1 = 4; //button pin, connect to ground to move servo
int press1 = 0;
Servo servo1;

void setup()
{
  pinMode(button1, INPUT);
  servo1.attach(7);
  digitalWrite(4, HIGH); //enable pullups to make pin high
}

void loop()
{
  press1 = digitalRead(button1);
  if (press1 == LOW)
  {
    servo1.write(160);
  }
  else {
    servo1.write(20);
  }
}
  digitalWrite(4, HIGH); //enable pullups to make pin high

What happened to the nice name?

My preference is to do this immediately after setting the mode, just to make it clear that the functions go together.