Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /mnt/nas/sobangcenter/public_html/sub08_01.html:15 Stack trace: #0 /mnt/nas/sobangcenter/public_html/sub08_01.html(15): mysqli_query() #1 {main} thrown in /mnt/nas/sobangcenter/public_html/sub08_01.html on line 15