php - MySQLi not able to select database -

i stuck website trying select new database. in earlier scripts went fine , able select databases , use them queries. time won't allow me change database , stays on previous one. line not work:

global $mysqli;  mysqli_select_db($mysqli, "new_database") or die("can't find it"); 

it stays earlier selected database...

thank help!

try one

 $con = mysqli_connect("localhost","root","","your_db");