How do I redirect after submit in PHP?

<?php
// Connect to DB
require('../admin/config.php');
 
// Start the session after logging in
session_start();
 
// Get the header info
  include'../functions/functions.php';
	echo getHeader('');
 
if (isset($_POST[ClientName])) {
 
    $link = @mysqli_connect('localhost', 'root', '', 'clients');
 
    if (mysqli_connect_errno()) {
 
        echo '<p class="error">Cannot connect to database server: ' . mysqli_connect_error() . '</p>';
 
    } else {
 
        $clientname       = mysqli_real_escape_string($link, $_POST['ClientName']);
        $clientcontact = mysqli_real_escape_string($link, $_POST['ClientContact']);
		$designrate = mysqli_real_escape_string($link, $_POST['DesignRate']);
		$devrate = mysqli_real_escape_string($link, $_POST['DevRate']);
        $clientsite    = mysqli_real_escape_string($link, $_POST['ClientSite']);
        $clientphone     = mysqli_real_escape_string($link, $_POST['ClientPhone']);
		$clientmobile     = mysqli_real_escape_string($link, $_POST['ClientMobile']);
		$clienthostingdate     = mysqli_real_escape_string($link, $_POST['ClientHostingDate']);
		$clienthostingcost     = mysqli_real_escape_string($link, $_POST['ClientHostingCost']);
		$clienttime     = mysqli_real_escape_string($link, $_POST['ClientTime']);
		$clientnote     = mysqli_real_escape_string($link, $_POST['ClientNote']);
 
 
        $query = "INSERT INTO clients (ClientName, ClientContact, ClientSite, ClientPhone, ClientMobile, DesignRate, DevRate, ClientNote) 
		VALUES ('$clientname', '$clientcontact', '$clientsite', 'clientphone', 'clientmobile', '$designrate', '$devrate', 'ClientNote')";
 
        $result = @mysqli_query($link, $query);
 
        if (!$result) {
 
            echo '<p class="error">Unable to query the database: ' . mysqli_error($link) . '</p>';
 
        } else {
 
            echo '<p class="success"><strong>' . stripslashes($clientname) . '</strong> has been added to the database.</p>';
			echo '<p>' . ($clientname) . '</p>';
			echo '<p>' . ($clientcontact) . '</p>';
 
            echo '<ul class="buttons">';
            echo '<li><a href="../admin/index.php">View Clients</a></li>';
            echo '<li><a href="' . $_SERVER['PHP_SELF'] . '">Add Record</a></li>';
            echo '</ul>';
 
        }
 
    }
 
} else {
 
?>
 
<h1>Create a New Client</h1>
 
        <form id="client_form" action="<?php echo $_SERVER['PHP_SELF']; ?>" method="post">
             
                <label for="ClientName">Client Name</label><br />
                <input id="ClientName" type="text" name="ClientName" /><br />
                <label for="ClientContact">Client Contact</label><br />
                <input id="ClientContact" type="text" name="ClientContact" /><br />
				<label for="DesignRate">Design Rate</label><br />
                <input id="DesignRate" type="text" name="DesignRate" /><br />
				<label for="DevRate">Development Rate</label><br />
                <input id="DevRate" type="text" name="DevRate" value="95" /><br />
                <label for="ClientPhone">Client Phone</label><br />
                <input id="ClientPhone" type="text" name="ClientPhone" /><br />
				<label for="ClientMobile">Client Mobile</label><br />
                <input id="ClientMobile" type="text" name="ClientMobile" /><br />
                <label for="ClientSite">Client Website</label><br />
                <input id="ClientSite" name="ClientSite" value="http://" /><br />
				<label for="ClientHostingDate">Client Hosting Date</label><br />
                <input id="ClientHostingCost" name="ClientHostingCost" /><br />
				<label for="ClientTime">Client Time</label> (Hrs)<br />
                <input id="ClientTime" name="ClientTime" /><br />
				<label for="ClientNote">Client Note</label><br />
				<textarea name="ClientNote" cols="40" rows="10"></textarea><br /><br />
				<input type="submit" value="Submit" name="submit" />      
        </form>
		
 
<?php
 
}
 
?>