<?php
$offset = $argv[0];
session_start();
if(!empty($_POST['regusername']))
{
  $connect = mysqli_connect("198.71.225.58", "password", "Cfh66n8*", "iapg");
  $output = '';
  $username = mysqli_real_escape_string($connect, $_POST['regusername']);
  $email = mysqli_real_escape_string($connect, $_POST['regemail']);
  $password = mysqli_real_escape_string($connect, $_POST['regpassword']);
  $name = mysqli_real_escape_string($connect, $_POST['regname']);
  $age = mysqli_real_escape_string($connect, $_POST['regage']);
  $disease = mysqli_real_escape_string($connect, $_POST['regdis']);

  $check = mysqli_query($connect, "SELECT * FROM users WHERE username = '$username'");

  if(mysqli_num_rows($check) > 0)
  {
    echo 'No';
  }
  else
  {
    $query = "INSERT INTO users(username, password, email, name, age, disease) VALUES('$username', '$password', '$email', '$name', '$age', '$disease')";
    if(mysqli_query($connect, $query))
    {
      echo 'Yes';
      $_SESSION['regusername'] = $_POST['regusername'];
    }
  }
}
?>