Dual stopwatch help

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7

i made some changes that was said and this is what i have it will start and stop on the right side but i dont know how to code it to put the left stop in when i do it ether want start or wont stop

#include <LiquidCrystal.h>

LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

int startbutPin = 8;//start button
int leftstopbutPin = 9;//left stop button
int rightstopbutPin = 10;//right stop button

void setup()
{
  lcd.begin(16, 2);
  lcd.clear();

  Serial.begin(9600);

  pinMode(startbutPin, INPUT);
  digitalWrite(startbutPin, HIGH);
  pinMode(leftstopbutPin, INPUT);
  digitalWrite(leftstopbutPin, HIGH);
  pinMode(rightstopbutPin, INPUT);
  digitalWrite(rightstopbutPin, HIGH);
}
double starttime = millis();
double leftet = 0;
double rightet = 0;
double leftstoptime;
double rightstoptime;

void loop()
{
  lcd.clear();
  lcd.print("Ready");
  delay(100);

  if (digitalRead(startbutPin) == LOW)
  {
    starttime = millis();
    while (digitalRead(rightstopbutPin) == HIGH)
    {
      leftstoptime = millis();
      rightstoptime = millis();
      leftet = (leftstoptime - starttime) / 1000;
      rightet = (leftstoptime - starttime) / 1000;
      lcd.clear();
      lcd.print(leftet);
      lcd.setCursor(12, 0);
      lcd.print("left");
      lcd.setCursor(0, 1);
      lcd.print(rightet);
      lcd.setCursor(11, 1);
      lcd.print("right");
      Serial.println(leftstoptime);
      Serial.println(starttime);
      Serial.println(leftet);
      Serial.println(rightstoptime);
      Serial.println(starttime);
      Serial.println(rightet);
      Serial.println("......");
      delay(100);
    }

    if (digitalRead(rightstopbutPin) == LOW)
    {
      while (digitalRead(startbutPin) == HIGH);
    }
  }
}

any idea on how to do this