我无法在我的数据库中插入数据。我哪里错了？

Here is my CODE. I'm using php 5.4 and the PDO connection! I included my database connection and some other files i need. And now I have a registration form wich i add some values from filling them. The ridirection is made and not a problem is shown. But when I check the DB is not added. Where I'm going wrong?Here is my CODE. I'm using php 5.4 and the PDO