Hello, i have 3 scripts for website which are meant to be allow user to login... i have finished register but i am having problem with login scripts.

Here are my 3 scritps, conf.inc.php is for configuration of variables, login.php is script which check login (i think there is source of problem.) and logger.php which is form.

I can register but when try to log in, it shows blank page with url of mywebsitename.com/login.php in url bar. Please help me.
Thanks in advance.
conf.inc.php

PHP Code:
<?php
$db_user 
"pfc"// Username
$db_pass "pfcpass"// Password
$db_database "users"// Database Name
$db_host "host"// Server Hostname
$db_connect mysql_connect ($db_host$db_user$db_pass); // Connects to the database.
$db_select mysql_select_db ($db_database); // Selects the database.
 
function form($data) { // Prevents SQL Injection
   
global $db_connect;
   
$data ereg_replace("[\'\")(;|`,<>]"""$data);
   
$data mysql_real_escape_string(trim($data), $db_connect);
   return 
stripslashes($data);
}
?>
logger.php

PHP Code:
<?php
echo '<div style="border-right: 2px gray; background-color:#555; border-radius:3px; display:inline; float:right; line-height:50px; padding:3px;"><span style="color:orchid;">New?</span><a href="register.php" class="round">SIGN UP</a></div>';
echo 
'<form id="form1" name="form1" method="post" action="login.php" class="logIn" style="background-color:#555; padding:2px; border: 1px solid #999; border-radius: 3px;">
        <span style="color:orchid;">Username: </span><input type="text" name="username" id="username" />
        <span style="color:orchid;">Password: </span><input type="password" name="password" id="password" /> &nbsp; &nbsp; &nbsp;
        <input type="submit" name="btnSubmit" id="logInBtn" value="Login" style="float:right;
    border-radius:2px;
    border: 1px solid gray;
    padding: 2px;
    background-color:black;
    color:white;
    margin-right:50px;"
    /> </form>'
;
    
?>
login.php

PHP Code:
<?php
include("conf.inc.php"); // Includes the db and form info.
session_start(); // Starts the session.
if ($_SESSION['logged'] == 1) { // User is already logged in.
    //echo '<script>document.getElementById("topRight").innerHTML += "You are logged in as"+ $_SESSION["member"] +"."</script>'; // Goes to main page.
    
echo '<script>document.getElementById("topRight").innerHTML += <a href="logout.php">Log Out</a></script>'// Goes to main page.
    
exit(); // Stops the rest of the script.
} else {
    if (isset(
$_POST['submit'])) { // The form has not been submitted.
        
$username form($_POST['username']);
        
$password md5(form($_POST['password'])); // Encrypts the password.
 
        
$q mysql_query("SELECT * FROM `users` WHERE username = '$username' AND password = '$password'") or die (mysql_error()); // mySQL query
        
$r mysql_num_rows($q); // Checks to see if anything is in the db. 
 
        
if ($r == 1) { // There is something in the db. The username/password match up.
            
$_SESSION['logged'] = 1;
            
// Sets the session.
            
echo 'Successfully logged in! <a href="index.html">Go to home page.</a>'// Goes to main page.
            
exit(); // Stops the rest of the script.
        
} else { // Invalid username/password.
            
exit("Incorrect username/password!"); // Stops the script with an error message.
        
//If invalid username and password. Cause they didn't matched, ends here.
    
};  // IF Form hasn't been submitted ends here.
}; //If session is not logged in ends here.
mysql_close($db_connect); // Closes the connection.
?>