Please help on Arduino : I wrote a program for Arduino for object avoiding using three ultrasonic sensors but it is giving error in compile. Can anyone suggest why is the error coming and how I can resolve it:

int trigPin = 6;<br/>
int echoPin = 7;<br/>
int trigPin = 8;<br/>
int echoPin = 9;<br/>
int trigPin = 10;<br/>
int echoPin = 11;<br/>
<br/>
int revleft4 = 2;<br/>
int fwdleft5 = 3;<br/>
int revright6 = 4;<br/>
int fwdright7 = 5;<br/>
<br/>
long duration, distance, RightSensor,FrontSensor,LeftSensor;<br/>
 <br/>
void setup()<br/>
{<br/>
delay(random(500,2000));<br/>
Serial.begin (9600);<br/>
pinMode(revleft4, OUTPUT);<br/>
pinMode(fwdleft5, OUTPUT);<br/>
pinMode(revright6, OUTPUT);<br/>
pinMode(fwdright7, OUTPUT);<br/>
<br/>
pinMode(trigPin1, OUTPUT);<br/>
pinMode(echoPin1, INPUT);<br/>
pinMode(trigPin2, OUTPUT);<br/>
pinMode(echoPin2, INPUT);<br/>
pinMode(trigPin3, OUTPUT);<br/>
pinMode(echoPin3, INPUT);<br/>
}<br/>
 <br/>
void loop() <br/>

SonarSensor(trigPin1, echoPin1);<br/>
RightSensor = distance;<br/>
SonarSensor(trigPin2, echoPin2);<br/>
LeftSensor = distance;<br/>
SonarSensor(trigPin3, echoPin3);<br/>
FrontSensor = distance;<br/>
<br/>
<br/>
if(FrontSensor<=20 && LeftSensor<=20)<br/>
{<br/>
  Serial.println("Turn right");<br/>
  digitalWrite(fwdright7,HIGH);<br/>
  digitalWrite(revright6,LOW);<br/>
  digitalWrite(fwdleft5,HIGH);<br/>
  digitalWrite(revleft4,LOW);<br/>
}<br/>
else if(FrontSensor<=20 && RightSensor<=20)<br/>
{<br/>
  Serial.println("Turn left");<br/>

  digitalWrite(fwdright7,LOW);<br/>
  digitalWrite(revright6,HIGH);<br/>
  digitalWrite(fwdright5,LOW);<br/>
  digitalWrite(revright4,HIGH);<br/>
}<br/>
else<br/>
{<br/>
  Serial.println("Forward");<br/>
<br/>
  digitalWrite(fwdright7,LOW);<br/>
  digitalWrite(revright6,HIGH);<br/>
  digitalWrite(fwdright5,HIGH);<br/>
  digitalWrite(revright4,LOW);<br/>
}<br/>
delay(5);<br/>
}<br/>
<br/>
 <br/>
void SonarSensor(int trigPin,int echoPin)<br/>
{<br/>
digitalWrite(trigPin, LOW);<br/>
delayMicroseconds(2);<br/>
digitalWrite(trigPin, HIGH);<br/>
delayMicroseconds(10);<br/>
digitalWrite(trigPin, LOW);<br/>
duration = pulseIn(echoPin, HIGH);<br/>
distance = duration/58.2; <br/>
}