What's wrong? Controlling void loops with integers.

advice: spend time to proper spacing, empty lines and indentation, makes code more readable

See the code below (not fixed all of the above)

// Reports the frequency from the TSL230, higher number means brighter
// Part: http://www.sparkfun.com/products/8940
// Article:  http://bildr.org/2011/08/tsl230r-arduino/ 

#include <Servo.h>

Servo myservo1;

int TSL230_Pin = 4;  //TSL230 output
int TSL230_s0 = 3;   //TSL230 sensitivity setting 1
int TSL230_s1 = 2;   //TSL230 sensitivity setting 2

int TSL230_samples = 30; //higher = slower but more stable and accurate

boolean once = false;

void setup()
{
  Serial.begin(9600);

  setupTSL230();

  pinMode(5,OUTPUT);
  myservo1.attach(5);
}


void loop()
{
  float lightLevel = readTSL230(TSL230_samples);

  Serial.println(lightLevel);

  if (lightLevel > 1800 && lightLevel < 10000 && once == true)
  {
     myservo1.writeMicroseconds(1300);delay(5000);
      myservo1.writeMicroseconds(1500);delay(5000);  
      once = false;
  }

  if (lightLevel < 1800 && once == false)
  {
    myservo1.writeMicroseconds(1700);delay(5000);
    myservo1.writeMicroseconds(1500);delay(5000);
    once = true;
  }
}

note readTSL230(TSL230_samples); is nowhere defined.