Problem With MySQL Not Being Able To Connect - Anyone know the reason for this error...

<?php
ob_start();
$host="hp2001.astahost.com"; // Host name
$username="hp2001"; // Mysql username
$password="********"; // Mysql password
$db_name="hp2001_ucscKGD"; // Database name
$tbl_name="members"; // Table name

// Connect to server and select database.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");

// Define $myusername and $mypassword
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];

$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);

// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row

if($count==1){
// Register $myusername and redirect to file "members.php"
session_register("myusername");
header("location:members.php");
}
else {
header("location:incorrectUP.php");
}

ob_end_flush();
?>

$host="hp2001.astahost.com"; // Host name
$username="hp2001"; // Mysql username
$password="********"; // Mysql password
$db_name="hp2001_ucscKGD"; // Database name
$tbl_name="members"; // Table name

$host="localhost"; // Host name
$username="hp2001"; // Mysql username (make this your username that you login to cPanel with)
$password="********"; // Mysql password(make this the password you login to astahost cPanel with)
$db_name="hp2001_ucscKGD"; // Database name
$tbl_name="members"; // Table name