Simple RC Car Programming Issue

Other Hardware Sensors
3

How would you make it that when you press the button (LED turns and stays on) and then when you let go of the button (LED goes off)?

UPDATED CODE:

int ir_pin = 2;				
int led_pin = 13;

int ledLEFT = 12;
int ledFORWARD = 11;
int ledBACK = 10;
int ledRIGHT = 8;
				
int debug = 1;				  
int start_bit = 2000;			
int bin_1 = 1000;				
int bin_0 = 400;				   


void setup() {
 pinMode(led_pin, OUTPUT);		
 pinMode(ir_pin, INPUT);
 
 pinMode(ledLEFT, OUTPUT);
 pinMode(ledFORWARD, OUTPUT);
 pinMode(ledBACK, OUTPUT);
 pinMode(ledRIGHT, OUTPUT);
 
 digitalWrite(led_pin, LOW);	
 
 Serial.begin(9600);
}

void loop() {
 int key = getIRKey();	 
 if (key != -1) {
   Serial.print("Key Received: ");
   Serial.println(key);
 }
 
  if (key == 16) {                           //To go left + forward.
   digitalWrite(ledLEFT, HIGH);
   digitalWrite(ledFORWARD, HIGH);
   digitalWrite(ledBACK, LOW);
   digitalWrite(ledRIGHT, LOW);
   delay(100);
   digitalWrite(ledFORWARD, LOW);
  }
  
  if (key == xxxx) {                         //To go forward.                         
   digitalWrite(ledLEFT, LOW);
   digitalWrite(ledFORWARD, HIGH); 
   digitalWrite(ledBACK, LOW);
   digitalWrite(ledRIGHT, LOW);
   delay(100);
   digitalWrite(ledFORWARD, LOW);
  }
  
  if (key == 1040) {                         //To go right + forward.
   digitalWrite(ledLEFT, LOW);
   digitalWrite(ledFORWARD, HIGH);
   digitalWrite(ledBACK, LOW); 
   digitalWrite(ledRIGHT, HIGH);
   delay(100);
   digitalWrite(ledFORWARD, LOW);
  }
  
  if (key == 2064) {                         //To go left + back.                         
   digitalWrite(ledLEFT, HIGH);
   digitalWrite(ledFORWARD, LOW); 
   digitalWrite(ledBACK, HIGH);
   digitalWrite(ledRIGHT, LOW);
   delay(100);
   digitalWrite(ledBACK, LOW);
  }
  
  if (key == 528) {                          //To go back. 
   digitalWrite(ledLEFT, LOW);
   digitalWrite(ledFORWARD, LOW); 
   digitalWrite(ledBACK, HIGH);
   digitalWrite(ledRIGHT, LOW);
   delay(100);
   digitalWrite(ledBACK, LOW);
  }
  
  if (key == xxxx) {                         //To go right + back. 
   digitalWrite(ledLEFT, LOW);
   digitalWrite(ledFORWARD, LOW); 
   digitalWrite(ledBACK, HIGH);
   digitalWrite(ledRIGHT, HIGH);
   delay(100);
   digitalWrite(ledBACK, LOW);
  }
  
  if (key == xxxx) {                         //To stop. 
   digitalWrite(ledLEFT, LOW);
   digitalWrite(ledFORWARD, LOW); 
   digitalWrite(ledBACK, LOW);
   digitalWrite(ledRIGHT, LOW);
   delay(100);
  }

}


int getIRKey() {
 int data[12];

 digitalWrite(led_pin, HIGH);     
 while(pulseIn(ir_pin, LOW) < 2200) { 
 }
 
 data[0] = pulseIn(ir_pin, LOW);	 
 data[1] = pulseIn(ir_pin, LOW);
 data[2] = pulseIn(ir_pin, LOW);
 data[3] = pulseIn(ir_pin, LOW);
 data[4] = pulseIn(ir_pin, LOW);
 data[5] = pulseIn(ir_pin, LOW);
 data[6] = pulseIn(ir_pin, LOW);
 data[7] = pulseIn(ir_pin, LOW);
 data[8] = pulseIn(ir_pin, LOW);
 data[9] = pulseIn(ir_pin, LOW);
 data[10] = pulseIn(ir_pin, LOW);
 data[11] = pulseIn(ir_pin, LOW);
 
 digitalWrite(led_pin, LOW);

 if(debug == 1) {
 }
 
 for(int i=0;i<=11;i++) {		    
   if (debug == 1) {  
   }
   
   if(data[i] > bin_1) {		    
	 data[i] = 1;
   } else {
	 if(data[i] > bin_0) {	     
	   data[i] = 0;
	 } else {
	  data[i] = 2;			  
	 }
   }
 }

 for(int i=0;i<=11;i++) {		     
   if(data[i] > 1) {
	 return -1;				
   }
 }

 int result = 0;
 int seed = 1;
 for(int i=11;i>=0;i--) {		  
   if(data[i] == 1) {
	 result += seed;
   }
   seed = seed * 2;
 }
  
 return result;				  
}