Untitled

<html>
<head>
<title> Input page </title>
</head>
<body>
<?php
if($_POST) {
    $username = "";
    $password = "";
    $database = "lettings";

    $mysqli = mysqli_connect("localhost", $username, $password, $database);


    if((!empty($_POST['address'])) && (!empty($_POST['rent'])) && (!empty($_POST['bedrooms'])))                                    {$address = mysqli_real_escape_string($_POST['address']);
        $rent = mysqli_real_escape_string($_POST['rent']);
        $bedrooms = mysqli_real_escape_string($_POST['bedrooms']);
    } else {
        echo "You left a field blank";
    }
$query = mysqli_query($mysqli, "INSERT INTO contacts VALUES ('', '".$address."', '".$rent."', '".$bedrooms."'"));
    mysqli_close($mysqli);
} else {
    //what to do in the event no post has been recieved at all, could be a blank submission, or could be the first loading of the page
}

?>

Input property data

<form method="post" action="">
<input type="text" name="address" id="address" />
<input type="submit" name="submit" value="Insert record" />
</form>
</body>
</html>