Unable to alert before redirecting to another php script using header() - header

Question

I was trying to create a dummy social networking site for practice. I'm stuck in a script which is sending friend request..
i've created a form(with a single text input, a hidden input and submit button) in which a logged in user can enter email address of a friend. When he clicks on the search button, he gets name and email of his friend(fetched using sql)..
With that i have added an anchor tag(named as Send request) displayed near the details. When a user clicks on the anchor tag, he is redirected to a new script which sends friend request to his friend. The second script only deals with mysql.
On sql completion, a user either gets "Friend Request Sent Successfully" alertbox or "Friend Request Already Sent" alertbox based on sql queries. Now i want to redirect the user to the first script after the execution of alertbox.
I tried to use header("Location: send_request.php") after the alertbox. But now it is redirecting user to the first script without showing alertbox.
Here is my first script(named as find_friends.php)
<?php
if(isset($_SESSION)) session_start();
require('header.php');
echo "<form method='POST' action=''>";
echo "<input type='text' name='search_user'/>";
echo "<input type='hidden' name='search_form_status' value='sent'/>";
echo "<input type='submit' value='Search User'/>";
echo "</form>";
if(isset($_POST['search_form_status']) && $_POST['search_form_status']=='sent'){
$search_user = $_POST['search_user'];
$sql_search_user = "SELECT id, name, email FROM registration where email=\"$search_user\"";
$query_search_user = mysql_query($sql_search_user);
$user_check = mysql_num_rows($query_search_user);
if($user_check==1){
$results_search_user = mysql_fetch_assoc($query_search_user);
echo $_SESSION['searched_id'] = $results_search_user['id'];
echo $_SESSION['searched_name'] = $results_search_user['name']."<br/>";
echo $_SESSION['searched_email'] = $results_search_user['email'];
echo "</br/><a href='send_request.php'>Send Request</a>";
}
}
?>
And here is second script(named as send_request.php)
<?php
$db1 = mysql_connect("localhost", "root", "");
mysql_select_db("test", $db1);
$db2 = mysql_connect("localhost", "root", "", true);
mysql_select_db("friends", $db2);
if(!isset($_SESSION)) session_start();
$searched_email = $_SESSION['searched_email'];
$searched_id = $_SESSION['searched_id'];
$user_name = $_SESSION['name'];
$user_email = $_SESSION['email'];
$sql_table_check = "SHOW TABLES LIKE 'friends_".$searched_id."'";
$table_check = mysql_num_rows(mysql_query($sql_table_check, $db2));
if($table_check==1){
$sql_insert_values = "INSERT INTO friends_".$searched_id." VALUES(\"\", \"$user_name\", \"$user_email\", 0)";
if(mysql_query($sql_insert_values)){
echo "<script>alert('Friends Request Sent Successfully')</script>";
header("Location: find_friends.php");
}
else{
echo "<script>alert('Friends Request Already Sent')</script>";
header("Location: find_friends.php");
}
}else{
$sql_create_table = "CREATE TABLE friends_".$searched_id." (friend_id MEDIUMINT NOT NULL AUTO_INCREMENT PRIMARY KEY, friend_name VARCHAR(30) NOT NULL, friend_email VARCHAR(50) NOT NULL UNIQUE, active TINYINT NOT NULL)";
$sql_insert_values = "INSERT INTO friends_".$searched_id." VALUES(\"\", \"$user_name\", \"$user_email\", 0)";
mysql_query($sql_create_table, $db2);
if(mysql_query($sql_insert_values, $db2)){
echo "<script>alert('Friends Request Sent Successfully')</script>";
}
}
?>

Answer 1

Try this:
if(mysql_query($sql_insert_values)){
echo "<script>
alert('Friends Request Sent Successfully');
window.location.href='find_friends.php';
</script>";
}