Simple PHP help (not inserting into array)

I've searched and searched and haven't found anything, though that's probably because I don't even know what's causing this bug, let alone how to fix it.

First off, I'm sort of new. I know the basics of PHP but there's a lot I don't know, so excuse me if the answer to this is simple (or if you can't read my code because it's so messy!).

I thought as one of my first applications I'd make a simple email script, where the user enters their name, subject, message, and email address.

This is the relevant bit of the form page: http://pastebin.com/UhQukUuB (sorry, don't quite know how to embed code...).

<form action="send.php" method="post">
    Name: <input type="text" name="name" size="20" /><br />
    Subject: <input type="text" name="subject" size="20" /><br />
    Message:<br /><textarea name="message" rows="12" cols="55"></textarea><br />
    Your email address: <input type="text" name="emailAddress" size="20" /><br />
    <input type="submit" value="Send" />
</form>

This is in send.php: http://pastebin.com/nky0L1dT .

<?php
    $name=$_POST['name'];
    $subject=$_POST['subject'];
    $message=$_POST['message'];
    $emailAddress=$_POST['emailAddress'];
    //It's receiving the variables correctly, I've checked by printing the variables.
    $errors=array(); //Creates empty array with 0 indexes. This will now be filled with error messages (if there are any errors).
    if($name=="" || $subject=="" || $message=="" || $emailAddress=""){
        if($name==""){
            $errors[0]="You did not supply a name.";
        }
        if($subject==""){
            $errors[count($errors)]="You did not supply a subject."; //I'm using count($errors) so it will create a new index at the end of the array, regardless of how many indexes it currently has (if that makes sense, it's hard to explain)
        }
        if($message==""){
            $errors[count($errors)]="You did not supply a message.";
        }
        if($emailAddress==""){
            $errors[count($errors)]="You did not supply an email address.";
        }
    }
    //Were there any errors?
    if(!count($errors)==0){
        print "The following errors were found:<br />";
        for($i=0; $i<count($errors); $i++){
            print $errors[$i]."<br />";
        }
        die ();
    }
    //Rest of email script, which I'll write when the stupid bug is fixed. :(
?>

Here's what happens: when you miss out the name, subject, or message, the error detector works fine and displays "You did not supply a name/subject/message". When you miss out the email address, nothing happens. I know it's being stored in the array and being received correctly, because if you miss out both the name/subject/message AND the email address, it displays "You did not supply a name/subject/message. You did not supply an email address". I've been staring at my screen for half an hour now just trying to spot why it's doing this?

Thanks.