HTTP error when trying to access mysql database - php

Question

Hey guys I'm still learning PHP and need help. I have 3 files that require a database.php file to connect to MySQL. when I execute the files only two of them work. For the last file, I get an HTTP error 500.
<?php
require( 'database.php');
// inserting information from the form into the database
$sql = ("INSERT INTO guestlist (firstName, lastName, phoneNumber,guests,event)
VALUES (?,?,?,?,?)");
// values are prepared to bind
$stmt = mysqli_prepare($con,$sql);
mysqli_stmt_bind_param($stmt,"sssss",$_POST['first_name'],$_POST['last_name'], $_POST['phonenumber'], $_POST['guest'], $_POST['event']);
$stmt->execute();
if (!$stmt)// Was not updated
{
// shows error
echo("There was an error with your RSVP. Please try again.");
mysqli_stmt_close($stmt);
}
else //Was updated
{
echo("Your RSVP has been completed.");
}
//End database connection
mysqli_close($con);
?>
this is my database file that was provided by my professor
<?php
$myHost = "localhost"; // localhost, do not change this string
$myUserName = "cmorales"; // CHANGE TO YOUR USERNAME
$myPassword = ""; // CHANGE TO YOUR PASSWORD
$myDataBaseName = "cmorales_project"; // CHANGE USERNAME
username_project
$con = mysqli_connect( "$myHost", "$myUserName", "$myPassword",
"$myDataBaseName" );
if( !$con ) // == null if creation of connection object failed
{
// report the error to the user, then exit program
die("connection object not created: ".mysqli_error($con));
}
if( mysqli_connect_errno() ) // returns false if no error occurred
{
// report the error to the user, then exit program
die("Connect failed: ".mysqli_connect_errno()." : ".
mysqli_connect_error());
}
?>

Answer 1

Because there is a syntax error in your database.php
Cause :
No semicolon end of username_project 7th line.
Solution:
remove undefined constant username_project on the 7th line.
as #Antonio Teh Sumtin mentioned in the comments, Always check the error log or enable the display error during development.