Undefined variable niggles

Undefined variable niggles

Below is my class. Fig A
<?php
class qcon{
public static $conn;
function dbcon()
{
if (!$conn)
{
$host = 'x';
$username = 'x';
$password = 'x';
$dbname = 'x';
$conn = mysqli_connect($host , $username , $password ,$dbname);
}
return $conn;
}
}
?>
Which is called here. Fig B
require_once(class file above);
function openSesame()
{
$boogey = new qcon();
$conn = $boogey->dbcon();
if (!$conn)
{
$this->error_msg = "connection error could not connect to the
database:! ";
return false;
}
$this->conn = $conn;
return true;
}
Is causing
Notice: Undefined variable: conn in C:\...\xxxx\figAclass.php on line 10
I know I can simply turn errors off, but this seems unwise. I took a look
at a generic SO question about the undefined variable notice. Obviously
the advice was general - use isset. Had a go at isset and this does not
seem correct for what I am trying to do.
Based on the code in figure A and B, is there anything obvious causing the
notice to be flagged up. Could you demonstrate a fix that is in line with
the existing code shown.