Warning: Undefined array key "site_cd" in C:\wamp64\www\EDSB\get_material_return_list.php on line 9

Fatal error: Uncaught TypeError: sqlsrv_query(): Argument #1 ($conn) must be of type resource, false given in C:\wamp64\www\EDSB\get_material_return_list.php:28 Stack trace: #0 C:\wamp64\www\EDSB\get_material_return_list.php(28): sqlsrv_query(false, 'SELECT \t\r\nmtr_m...') #1 {main} thrown in C:\wamp64\www\EDSB\get_material_return_list.php on line 28