I'm using Drupal 7 and have created a content type called abc. In abc there is a field called seller. When a logged in user creates a new piece of abc content, the value of the seller field would be the name of the person who is logged in.
So what I want is a default value for the seller field for a small piece of PHP code. But I am not able to find the place to enter this PHP. In Drupal 6 there is text area for the php code to enter, how can this be done with Drupal 7.