Problem displaying LCD message, Starter Kit Mega 2560

Hey! I started working on the LCD project yesterday but I can’t get it to display anything. It turns on and the code appears to work properly but the message isn’t displayed. I included below the wiring diagram and what I made. I also included the code because I really don’t know if the error might be there. Any help would be appreciated, thanks!

#include <LiquidCrystal.h>

// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("Hellow world");

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);
  // print the number of seconds since reset:
  lcd.print(millis() / 1000);

What I made following the wiring model

It looks like you may have crossed the wires from Mega 11 & 12 to LCD D6 & D7. The picture is a little unclear. Also, make sure your contrast pot is set for minimal resistance. The closer the contrast pin is to ground the darker the characters. From your picture it looks like full clockwise.

It worked, it was the contrast thanks a lot!