registration script keeps showing errors when all fields are filled - forms

Question

Im having a little issue with my registration script.
I am trying to add rows into my mysql database.
This is my form verifier to make sure all fields are filled:
//Variables from the table
$user = $_POST['un'];
$pass = $_POST['pw'];
$rpass = $_POST['rpw'];
//Prevent MySQL Injections
$user = stripslashes($user);
$pass = stripslashes($pass);
$rpass = stripslashes($rpass);
$user = mysqli_real_escape_string($user);
$pass = mysqli_real_escape_string($pass);
$rpass = mysqli_real_escape_string($rpass);
//Check to see if the user left any space empty!
if($user == "" || $pass == "" || $rpass == "")
{
echo "Please fill in all the information!";
}
and this is the form
<form action="register_proc.php" method="post">
<label for="un">Username</label>
<input type="text" name="un" id="un" placeholder="username"/>
<br/>
<label for="pw">Password</label>
<input type="password" name="pw" id="pw" placeholder="password"/>
<br/>
<label for="rpw">Repeat Password</label>
<input type="password" name="rpw" id="rpw" placeholder="repeat password"/>
<br/>
<input type="submit" name="submit" value="Complete Registration"><br>
<div style="float: left;">
Home
</div>
<div style="float: right;">
Login
</div>
</form>
I have no idea why it keeps outputting the else statment "Please fill in all the information!"
All of the $post variables have the correct names
thank you for the upcoming support.