I'm creating a small website with a game for a customer. They wanted to connect everything with Facebook, so I implemented the Facebook registration plugin. (https://developers.facebook.com/docs.../registration/ with XFBML).

Now the customer wanted a second registration/login-box.
Here's my form:
HTML Code:
<form method="post" action="<?php echo $_SERVER['PHP_SELF']; ?>">
	Name: <input type="text" name="name"><br>
	E-Mail: <input name="email"></textarea><br>
	I'm already a customer:
	<input type="radio" name="customer" value="yes">
	<input type="radio" name="customer" value="no">
	<input type="submit" name="Button" value="Register">
Now there's a problem: I can't enter text into those fields. I made an empty HTML-file with just the form and it works. I have no idea what could be causing that.

I can access it via Tab and can click it so I can see the values I've entered in other fields. I can choose between the radio buttons by pressing the left/right arrow key. But I can't write or select the text or anything.

Any idea?