그누보드4 설치중입니다

오류 메시지 해결방안좀 부탁드립니다 ㅠㅠ
인스톨시 밑에 같은 메시지가 뜨는데

Warning: Use of undefined constant mysql_host - assumed 'mysql_host' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 25

Warning: Use of undefined constant mysql_user - assumed 'mysql_user' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 26

Warning: Use of undefined constant mysql_pass - assumed 'mysql_pass' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 27

Warning: Use of undefined constant mysql_db - assumed 'mysql_db' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 28

Warning: Use of undefined constant admin_id - assumed 'admin_id' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 29

Warning: Use of undefined constant admin_pass - assumed 'admin_pass' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 30

Warning: Use of undefined constant admin_name - assumed 'admin_name' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 31

Warning: Use of undefined constant admin_email - assumed 'admin_email' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 32

Warning: Use of undefined constant charset - assumed 'charset' (this will throw an Error in a future version of PHP) in /home/boomfile/html/install/install_db.php on line 34

Fatal error: Uncaught Error: Call to undefined function mysql_query() in /home/boomfile/html/install/install_db.php:34 Stack trace: #0 {main} thrown in /home/boomfile/html/install/install_db.php on line 34

인스톨 디비 php 파일을 보면

$mysql_host  = $_POST[mysql_host];
$mysql_user  = $_POST[mysql_user];
$mysql_pass  = $_POST[mysql_pass];
$mysql_db    = $_POST[mysql_db];
$admin_id    = $_POST[admin_id];
$admin_pass  = $_POST[admin_pass];
$admin_name  = $_POST[admin_name];
$admin_email = $_POST[admin_email];

if (strtolower($g4[charset]) == 'utf-8') @mysql_query("set names utf8");

이렇게 되어 있는데 어떻게 수정을 해줘야 되는건가요?