mysql database connection using php

Question

plz help me.i am developing a webpage .i want to connect mysql database by using php .i did connection code in php. but i did't get the connection.

here i am attach what i did. if any one knows how to connect mysql database plz send the answer. 

 

 

 

<?php

$dbhost = "localhost";

$username = "root";

$password = "";

$dbname = "test";

$conn = mysql_connect($dbhost,$username,$password) or die ("db error");

$select_db = mysql_select_db($dbname) or die ("cloud not select db");

$db=mysql_select_db("test",$conn);

$query=mysql_query("select * from local_bus",$db);

?>