Upload the code of the car can go straight, want to ask is a code, or other problems

Int xunxianPin1=8;
Int xunxianPin2=9;
Int xunxianPin3=12;
Int xunxianPin4=13;
Int IN1=4;
Int IN2=5;
Int IN3=6;
Int IN4=7;
Int buttonState=0;
Int EN1=10;//can make port 1
Int EN2=11;//can make port 2
Int L1, L2, R1, R2;
Void forward ()
{
DigitalWrite (IN1, HIGH);
DigitalWrite (IN2, LOW);
DigitalWrite (IN3, HIGH);
DigitalWrite (IN4, LOW);
AnalogWrite (EN1, 255);
AnalogWrite (EN2, 255);
}
Void back ()
{
DigitalWrite (IN1, LOW);
DigitalWrite (IN2, HIGH);
DigitalWrite (IN3, LOW);
DigitalWrite (IN4, HIGH);
AnalogWrite (EN1, 255);
AnalogWrite (EN2, 255);

}
The void left ()
{
DigitalWrite (IN1, LOW);
DigitalWrite (IN2, HIGH);
DigitalWrite (IN3, HIGH);
DigitalWrite (IN4, LOW);
AnalogWrite (EN1, 255);
AnalogWrite (EN2, 255);
}
Void right ()
{
DigitalWrite (IN1, HIGH);
DigitalWrite (IN2, LOW);
DigitalWrite (IN3, LOW);
DigitalWrite (IN4, HIGH);
AnalogWrite (EN1, 255);
AnalogWrite (EN2, 255);
}
Void setup () {
PinMode (IN1, the OUTPUT);
PinMode (IN2, the OUTPUT);
PinMode (IN3, the OUTPUT);
PinMode (IN4, the OUTPUT);
PinMode (xunxianPin1, INPUT);
PinMode (xunxianPin2, INPUT);
PinMode (xunxianPin3, INPUT);
PinMode (xunxianPin4, INPUT);
}


Void loop () {
L1=digitalRead (8);
L2=digitalRead (9);
R1=digitalRead (12);
R2=digitalRead (13);
Forward ();
If (L1==LOW& & L2==HIGH& & R1==HIGH& & R2==HIGH)
{
The left ();
Delay (50);
}
If (L1==HIGH& & L2==HIGH& & R1==HIGH& & R2==LOW)
{
Right ();
Delay (50);
}

}