To input data use
db_query("INSERT INTO users (email, name, password) VALUES ('{$email}', '{$name}', '{$password}')");
and I using variable $ so you need to set
$email = $_POST['email']
and for name password and other thing you need to put in to your database
then for HTML you can do
HTML:
<form action="register.php" method="post">
<input type="hidden" name="page_mode" value="register">
<div class="left_box">Email address</div>
<div class="right_box"><input type="text" name="email" size="30" maxlength="255" value="<?php if (isset($email)) echo $email; ?>"></div>
<div class="left_box">Name</div>
<div class="right_box"><input type="text" name="name" size="30" maxlength="255" value="<?php if (isset($name)) echo $name; ?>"></div>
<div class="left_box">Password</div>
<div class="right_box"><input type="password" name="password" size="30"></div>
<div class="left_box"> </div>
<div class="right_box"><input type="submit" value="Register" size="30"></div>
If you want a register system you will need
-verify input email is a real email
-verify if comfirm password the same as password
-verify if username in use...
but if you just want to input data to database then the code i put should work fine ( I don't really understand your purpose of inputting data so can't give you advise)