int switch_state;
void setup()
{
Serial.begin(9600);
pinMode(13,OUTPUT);
pinMode(4,INPUT);
}
void loop()
{
switch_state = digitalRead(4);
if (switch_state==1)
digitalWrite(13, LOW);
else
digitalWrite(13, HIGH);
/* --(end main loop )-- */
Serial.println(switch_state);
//delay(1000);
}