Control servo with push - button

I am very new here , I want to control a servo by push – button.
Push/Hold button servo move 80* to 30* / 30* to 80* non-stop , release buttom and servo stop at 80.

How do i wirte these code? thks

Well first have a look at this servo tutorial if you haven't already- you'll easily see where to change the 0-180 to suit your 30-80 requirement.

Then have a look at how to read the state of a button which turns on a led.

Lastly give a bit of thought as to how to incorporate the servo sweep program, into the second one instead of controlling the led.

(It's much better if you try this yourself with the above pointers, rather than getting a ready-made solution from someone 8) )

Very simple code you might add a sweep function to when the button is depressed.

//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);
  }
}