Warning: Undefined array key "nos" in /var/www/html/iteach4u/htdocs/2017/studymaterials/downloadLayer.php on line 12

Warning: Undefined variable $connect in /var/www/html/iteach4u/htdocs/2017/studymaterials/downloadLayer.php on line 21

Fatal error: Uncaught TypeError: mysqli_query(): Argument #1 ($mysql) must be of type mysqli, null given in /var/www/html/iteach4u/htdocs/2017/studymaterials/downloadLayer.php:21
Stack trace:
#0 /var/www/html/iteach4u/htdocs/2017/studymaterials/downloadLayer.php(21): mysqli_query(NULL, 'select no, file...')
#1 {main}
  thrown in /var/www/html/iteach4u/htdocs/2017/studymaterials/downloadLayer.php on line 21