I am looking for a method to check whether a user has entered something into a login script or not. I have tried 
`if (!empty($_POST))` 
but this method failed. As I am new to php I am not sure as to what other clean method to use.

```
<?php
    if ( !empty($post)){
    header("Location:login.php");
    echo"Invalid Username or Password";
    }
?>
<html>
    <head>
        <title>Administrator Login Page</title>
        <style type="text/css">
            @import "style.css";
        </style>
    </head>
    <body>
        <h1>Administrator Login Page</h1>
        </br></br></br></br></br></br></br>
        <form action="admin_verify.php" method="post">
            User Name:
            <input type="text" name="admin_name" />
            </br></br>
            Password:&nbsp;&nbsp;
            <input type="password" name="admin_password" />
            </br></br>
            &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
            <input type="submit" value="Login"/>
            <input type="reset" value="Reset"/>
        </form>
    </body>
</html>

```