Control two stepper motors' speed and direction with two analog inputs (joystick). By Eduardo Rivas, David Escobar and Ángel Moreno for Universidad Don Bosco de El Salvador, 2013.

twin_motor_control.ino

/* 
Dual Stepper Motor Control (Arduino UNO R3)
Controls the speed and direction of two stepper motors
via two analog inputs. Used to achieve two-dimensional
movement controlled by a joystick. End-of-track sensors
prevent damage to the structure and motors.

Based on "Speed Control" example of the Stepper lib.
Please note the Stepper library produces a bipolar sequence.
By swapping the two middle cables, a unipolar seq. is obtained.

By Eduardo Rivas, David Escobar y Ángel Moreno
for Universidad Don Bosco of El Salvador, 2013.
 */

#include <Stepper.h>

// Set steps per revolution
const int PPR = 200;

// Motor Y in pins 10-13
Stepper motor1(PPR, 10,11,12,13);
// Motor X in pins 6-9
Stepper motor2(PPR, 6,7,8,9);

void setup() {
  // Pins 2-5 set up as inputs with pullup resistors. Sensors are active-low.
  for (int i = 2; i <= 5; i++)
  {
    pinMode(i, INPUT_PULLUP);
  }
}

void loop() {
  // MOTOR 1 CONTROL
  int speed = 0;
  int direction = 1;
  // Get joystick position on A1
  int position = analogRead(1);

  /*
  Values between 562 and 1023 mean forward movement. Speed gets
  mapped from 0 to 10 and direction stays positive. Sensors will
  block any movement if HIGH.
  */
  if (position > 562 and digitalRead(2) == HIGH) {
    speed = map(position, 562, 1023, 0, 10);
  }
  /*
  Values between 0 and 462 mean backwards movement. Speed gets
  mapped from 10 to 0 and direction is negative. Sensors will
  block any movement if HIGH.
  */
  if (position < 462 and digitalRead(3) == HIGH) {
    speed = map(position, 0, 462, 10, 0);
    direction = -1;
  }
  // Values between 462 and 562 mean no movement (joystick center zone)
  if (speed > 0) {
    motor1.setSpeed(speed);
    motor1.step(direction);
  }

  // MOTOR 2 CONTROL
  speed = 0;
  direction = 1;
  position = analogRead(2);

  if (position > 562 and digitalRead(4) == HIGH) {
    speed = map(position, 562, 1023, 0, 10);
  }

  if (position < 462 and digitalRead(5) == HIGH) {
    speed = map(position, 0, 462, 10, 0);
    direction = -1;
  }

  if (speed > 0) {
    motor2.setSpeed(speed);
    motor2.step(direction);
  }
}

This is a great one. any one can rewrite the code automatically without joystick.
if any comment. mebituassefa12@gmail.com is my address.