Else' without a previous 'if'

Cordial saludo soy nuevo conb la programacion de arduino, estoy realizando un proyecto de un carro detector de lineas, ceo los comandos y al compilar me da el siguiente error else' without a previous 'if'

este son los comando ingresados, no se donde me estoy equibocando

unsigned long x,y,z;
float s1,s2,s3,s4,s5;
int pwm=100;
int color=350;
int vl=pwm+60;
int vh=pwm-60;
void setup() {
Serial.begin(9600);
pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
}

void loop(){
ceros:
analogWrite(3,0);
analogWrite(5,0);
inicio:
digitalWrite(4,LOW);
s1=analogRead(1);
s2=analogRead(2);
s3=analogRead(3);
s4=analogRead(4);
s5=analogRead(5);
if (s3>=color){
analogWrite(3,pwm);
analogWrite(5,pwm);
x=millis();
goto inicio;
}
else if (s1>=color) //Extrema Izquierda
{
analogWrite(3,vl); //Motor Derecho
analogWrite(5,vh); //Motor Izquierdo
x=millis();
goto inicio;
}
else if (s5>=color) //Extrema Derecha
{
analogWrite(3,vh); //Motor Derecho
analogWrite(5,vl); //Motor Izquierdo
x=millis();
goto inicio;
}
else if (s2>=color); //Medio Izquierdo
{
analogWrite(3,pwm);
analogWrite(5,vh);
x=millis();
goto inicio;
}
else if (s4>=color); //Medeio Derecha
{
analogWrite(3,vh); //Motor Derecho
analogWrite(5,pwm); //Motor Izquierdo
x=millis();
goto inicio;
}
else {
digitalWrite(4,HIGH);
y=millis();
z=y=x;
if(z<=1000)
{
goto inicio;
}
else {
goto ceros;
}
}
}

Read the forum guidelines to see how to properly post code and some hints on how to get the most from this forum.
Use the IDE autoformat tool (ctrl-t or Tools, Auto format) before posting code in code tags.

Please include the entire error message. It is easy to do. There is a button (lower right of the IDE window) called "copy error message". Copy the error and paste into a post in code tags. Paraphrasing the error message leaves out important information.

else if (s2 >= color);
else if (s4 >= color);

Ending the else if (or any if) with a semi colon is a mistake.

Here is your code posted properly in code tags and formatted. I removed the bad semicolons and now the code compiles with no warnings or errors.

unsigned long x, y, z;
float s1, s2, s3, s4, s5;
int pwm = 100;
int color = 350;
int vl = pwm + 60;
int vh = pwm - 60;

void setup()
{
   Serial.begin(9600);
   pinMode(3, OUTPUT);
   pinMode(4, OUTPUT);
   pinMode(5, OUTPUT);
}

void loop()
{
ceros:
   analogWrite(3, 0);
   analogWrite(5, 0);
inicio:
   digitalWrite(4, LOW);
   s1 = analogRead(1);
   s2 = analogRead(2);
   s3 = analogRead(3);
   s4 = analogRead(4);
   s5 = analogRead(5);
   if (s3 >= color)
   {
      analogWrite(3, pwm);
      analogWrite(5, pwm);
      x = millis();
      goto inicio;
   }
   else if (s1 >= color) //Extrema Izquierda
   {
      analogWrite(3, vl); //Motor Derecho
      analogWrite(5, vh); //Motor Izquierdo
      x = millis();
      goto inicio;
   }
   else if (s5 >= color) //Extrema Derecha
   {
      analogWrite(3, vh); //Motor Derecho
      analogWrite(5, vl); //Motor Izquierdo
      x = millis();
      goto inicio;
   }
   else if (s2 >= color) //Medio Izquierdo ******* removed ;
   {
      analogWrite(3, pwm);
      analogWrite(5, vh);
      x = millis();
      goto inicio;
   }
   else if (s4 >= color) //Medeio Derecha   ******* removed ;
   {
      analogWrite(3, vh); //Motor Derecho
      analogWrite(5, pwm); //Motor Izquierdo
      x = millis();
      goto inicio;
   }
   else
   {
      digitalWrite(4, HIGH);
      y = millis();
      z = y = x;
      if (z <= 1000)
      {
         goto inicio;
      }
      else
      {
         goto ceros;
      }
   }
}

Since the 1980s we don't use goto. In C++ ( the language of Arduino) we use functions.

Gracias ya me funciono