I assume that's what the mysql anchor is for. Try this.
$conn_one = mysql_connect($host_one, $username_one, $pass_one) or die(mysql_error());
$conn_two = mysql_connect($host_two,$username_two, $pass_two) or die(mysql_error());
$db_one = mysql_select_db($db_one, $conn_one) or die(mysql_error());
$db_two = mysql_select_db($db_two, $conn_two) or die(mysql_error());
$sql_one = "SELECT FROM $table_one";
$sql_two = "SELECT FROM $table_two";
$result_one = mysql_query($sql_one,$conn_one) or die(mysql_error());
$result_two = mysql_query($sql_two, $conn_two) or die(mysql_error());
Hope this helps
Good luck
Rob