If statement error with expected unqualified id

I put a while statement inside my if statement and it's thrown "expected unqualified-id before'if'" at me. I'm not entirely sure what this means or how to fix it. The idea behind the code is to make a robot move towards the brightest light using LDRs, and I've tried to include a 40 unit buffer between LDRs before it begins to turn.

//LDR pins
const int leftLDR = A1;
const int rightLDR = A2;

//Motor settings
int LeftDirection = 2;
int LeftEnable = 3;
int RightDirection = 4;
int RightEnable = 5;
int speed = 150;

//Buffer for the LDR readings of 40
int threshholdBufferUpperCap = 80;
int threshholdBufferLowerCap = 40;

void setup() {
  Serial.begin(9600); //Hardware baud rate

  //Initilizing pin modes
  pinMode(leftLDR, INPUT);
  pinMode(rightLDR, INPUT);

  pinMode(LeftDirection, OUTPUT);
  pinMode(LeftEnable, OUTPUT);
  pinMode(RightDirection, OUTPUT);
  pinMode(RightEnable, OUTPUT);

}

void loop() {

  //HIGH means the wheels move forwards, LOW means they move backwards.
  digitalWrite(LeftDirection, HIGH);
  analogWrite(LeftEnable, speed);
  digitalWrite(RightDirection, HIGH);
  analogWrite(RightEnable, speed);

 //Take reading from LDRs
 int ldrLeftThreshhold = analogRead(leftLDR);
 int ldrRightThreshhold = analogRead(rightLDR);

  //if statement so the robot turns towards a light if theres more light hitting the left LDR
  if (ldrLeftThreshhold > threshholdBufferUpperCap){

  while (ldrRightThreshhold < threshholdBufferLowerCap) {

  }
 }
 //Stop the motors as a sudden direction change might damage the motor
 int speed = 0;
 delay(250);
 digitalWrite(RightDirection, LOW); //Motors moving different directions to allow turning
 delay(50);
 speed = 150;
}

if (ldrRightThreshhold > threshholdBufferUpperCap){

 while (ldrLeftThreshhold < threshholdBufferLowerCap) {

  }
 }
 //Stop the motors as a sudden direction change might damage the motor
 int speed = 0;
 delay(250);
 digitalWrite(LeftDirection, LOW); //Motors moving different directions to allow turning
 delay(50);
 speed = 150;
}

//Print to serial monitor a quantified measure for the amount of light hitting the LDRs
Serial.print("Left LDR threshhold - ");
Serial.println(ldrLeftThreshhold);
Serial.print("Right LDR threshhold - ");
Serial.println(ldrRightThreshhold);
delay(1500);
}