trying to fix errors

I've been working on my first sketch and I finished the first draft. There are errors, it is a work in progress. I've been trying to figure out the first error but my research hasn't helped. I'm using an Arduino Uno, the attoparsec.com EL Wire Interface Kit and the Adafruit Motor Shield V2 for Arduino. Any help would be appreciated.

Zapper_Effect:24: error: expected constructor, destructor, or type conversion before '->' token
Zapper_Effect:25: error: expected constructor, destructor, or type conversion before '->' token
Zapper_Effect.ino: In function 'void loop()':
Zapper_Effect:60: error: 'Low' was not declared in this scope
Zapper_Effect:69: error: 'string' was not declared in this scope
Zapper_Effect.ino: In function 'void all_off()':
Zapper_Effect:103: error: 'If' was not declared in this scope
Zapper_Effect:103: error: expected `;' before 'counter'

#include <Wire.h>                      //calling adafruit library
#include <Adafruit_MotorShield.h>      //calling adafruit library
#include "utility/Adafruit_PWMServoDriver.h"

Adafruit_MotorShield AFMS = Adafruit_MotorShield();    // Create the motor shield object with the default I2C address
Adafruit_DCMotor *el_inverter = AFMS.getMotor(1);       // assigning the inverter to M1 or port 1

el_inverter->setSpeed(255);                             // sets the default speed to 100%
el_inverter->run(FORWARD);                              // turns the inverter on

int counter = 0;
int button_state;                                       // related to push button
int button = false;                                     // related to push button
int trigger = 17;
int LEDPin = 13;
#define A  2
#define pulse_width  3

void on(char);
void off(char);
void all_on(void);
void all_off(void);
void fade_in(char);
void fade_out(char);

void setup()                    // run once, when the sketch starts
{
  all_off();
  AFMS.begin();                                          // Connect to the Controller
  pinMode (8, INPUT_PULLUP);    // enables pullup resistor for push buton on pin 8
  pinMode(trigger, OUTPUT);
  pinMode(3, OUTPUT);           // sets digital pin 3 as output for connecting to attoparsec zapper arm circuit                         
  pinMode (LEDPin, OUTPUT);     // like on original sketch
  digitalWrite(trigger, HIGH);
}

void loop()                     // run over and over again
{
  if (button_state == 1) {
    button = false; 
  }
  else { 
    if (button_state == 0)
      LEDPin = Low;
    digitalWrite(trigger, LOW);
    digitalWrite(LEDPin, HIGH);
    delay(300);
    digitalWrite(trigger, HIGH);
    digitalWrite(LEDPin, LOW);

    if (counter < 3){
      counter = counter + 1; 
      fade_in(string);
      delay(5);
      fade_out(string);
    }
    delay(500);
  }
}

void fade_in(char channel)
{
  for(int brightness=0; brightness<=pulse_width; brightness++){
    for(int duration=0; duration<1; duration++){
      on(channel);
      delay(brightness);
      off(channel);
      delay(pulse_width-brightness);
    }
  }
  on(channel);
}

void fade_out(char channel)
{
  for(int brightness=pulse_width; brightness>=0; brightness--){
    for(int duration=0; duration<1; duration++){
      on(channel);
      delay(brightness);
      off(channel);
      delay(pulse_width-brightness);
    }
  }
}
void all_off(void)
{
  If counter >= 3
    off(i);
}
void off(char channel)
{
  pinMode(channel, INPUT);
}
void on(char channel)
{
  pinMode(channel, OUTPUT);
  digitalWrite(channel, LOW); 
}

Paraphrasing errors

Zapper_Effect:24: error: expected constructor, destructor, or type conversion before '->' token
Zapper_Effect:25: error: expected constructor, destructor, or type conversion before '->' token
These symbols shouldn't be here in there code. Something is wrong.

Zapper_Effect.ino: In function 'void loop()':
Zapper_Effect:60: error: 'Low' was not declared in this scope
Zapper_Effect:69: error: 'string' was not declared in this scope
There is no variable named "Low" or "string" declared in the loop(). FYI Low and LOW are NOT the same thing as everything is case sensitive.

Zapper_Effect.ino: In function 'void all_off()':
Zapper_Effect:103: error: 'If' was not declared in this scope
Zapper_Effect:103: error: expected `;' before 'counter'
There is a set of {}'s and ()'s missing for the 'all_off" function.

*Edit:

Add-on for that first error about the "->"
From the PDF for the motor shield, please not the bold section:

Create the DC motor object
Request the Stepper motor from the Adafruit_MotorShield:
Adafruit_DCMotor *myMotor = AFMS.getMotor(1);
with getMotor(port#). Port# is which port it is connected to. If you're using M1 its 1, M2
use 2, M3 use 3 and M4 use 4

Connect to the Controller
In your setup() function, call 'begin()" on the Adafruit_MotorShield object:
AFMS.begin();

Set default speed
Set the speed of the motor using setSpeed(speed) where the speed ranges from 0
(stopped) to 255 (full speed). You can set the speed whenever you want.
myMotor->setSpeed(100);

These

el_inverter->setSpeed(255);                             // sets the default speed to 100%
el_inverter->run(FORWARD);                              // turns the inverter on

must be inside a function.

  If counter >= 3Have you ever seen "if" spelled like that, or an "if" expression constructed like that?

Thank you for the help, it put me on the right path. I've made quite a few changes to the code, but I'm still getting a few errors. I'm really not sure what's causing it.

Zapper_Effect.ino: In function 'void loop()':
Zapper_Effect:38: error: too many arguments to function 'void all_off()'
Zapper_Effect:75: error: at this point in file

#include <Wire.h>                      //calling adafruit library
#include <Adafruit_MotorShield.h>      //calling adafruit library
#include "utility/Adafruit_PWMServoDriver.h"

/* This code is meant to create a taser-like effect. 
 * It is based on the EL Ladder project on digitalmisery.com written by Ryan Owens
 *
 * Zapper_Effect
 * 
 * 
 *
 * This code was written to utilize an Arduino Uno, the attoparsec.com EL Wire Interface Kit and the Adafruit Motor Shield V2 for Arduino.
 * 
 *
 * 
 */

Adafruit_MotorShield AFMS = Adafruit_MotorShield();     // Create the motor shield object with the default I2C address
Adafruit_DCMotor *el_inverter = AFMS.getMotor(1);       // assigning the inverter to M1 or port 1


int counter = 0;
int button_state;                                       // related to push button
int button = false;                                     // related to push button
int trigger = 17;
int LEDPin = 13;                                        // built-in LED connected to digital pin 13 ON Arduino Uno
int A;
#define A  2                                            //can probably delete this line
#define pulse_width  3

void on(char);
void off(char);
void all_on(void);
void all_off(void);
void fade_in(char);
void fade_out(char);

void setup()                    // run once, when the sketch starts
{
  all_off();
  AFMS.begin();           // Connect to the Controller
  el_inverter->setSpeed(255);                             // sets the default speed to 100%
  el_inverter->run(FORWARD);                              // turns the inverter on
  pinMode (8, INPUT_PULLUP);    // enables pullup resistor for push buton on pin 8
  pinMode(trigger, OUTPUT);
  pinMode(3, OUTPUT);           // sets digital pin 3 as output for connecting to attoparsec zapper arm circuit                         
  pinMode (LEDPin, OUTPUT);     // like on original sketch
  digitalWrite(trigger, HIGH);
  }

void loop()                     // run over and over again
{
  if (button_state == 1) {
      button = false; }
  else if (button_state == 0)
      { LEDPin = HIGH;                                    // When the pin is HIGH value, the LED is on
      digitalWrite(trigger, LOW);
      digitalWrite(LEDPin, HIGH);
      delay(300);
      digitalWrite(trigger, HIGH);
      digitalWrite(LEDPin, LOW);
      
      if (counter < 3){
      counter = counter + 1; 
      fade_in(A);
      delay(5);
      fade_out(A); }
    
      else if (counter >= 3) {
      delay(500);  
      all_off(A); }
      }
    
}

void fade_in(char channel)
{
	for(int brightness=0; brightness<=pulse_width; brightness++){
		for(int duration=0; duration<1; duration++){
			on(channel);
			delay(brightness);
			off(channel);
			delay(pulse_width-brightness);
		}
	}
	on(channel);
}

void fade_out(char channel)
{
	for(int brightness=pulse_width; brightness>=0; brightness--){
		for(int duration=0; duration<1; duration++){
			on(channel);
			delay(brightness);
			off(channel);
			delay(pulse_width-brightness);
		}
	}
}
void all_off(void)
 
{
        off(A);
        el_inverter->run(RELEASE);                              // Cuts power to the motor, stop rotation, turns off the inverter
        el_inverter->setSpeed(0);                               // stop
        LEDPin = LOW;                                           // When the pin is LOW value, the LED is off
        void release(void);
}
all_off(A);

In this case, "too many" includes one.