Var is an object var. Add missing this.

git-svn-id: https://develop.svn.wordpress.org/branches/2.2@5426 602fd350-edb4-49c9-b593-d223f7449a82

wp-admin/import/wordpress.php

@@ -65,7 +65,7 @@ function checkauthor($author) {
 			$this->mtnames[$this->j] = $author; //add that new mt author name to an array
 			$user_id = username_exists($this->newauthornames[$this->j]); //check if the new author name defined by the user is a pre-existing wp user
 			if (!$user_id) { //banging my head against the desk now.
-				if ($newauthornames[$this->j] == 'left_blank') { //check if the user does not want to change the authorname
+				if ($this->newauthornames[$this->j] == 'left_blank') { //check if the user does not want to change the authorname
 					$user_id = wp_create_user($author, $pass);
 					$this->newauthornames[$this->j] = $author; //now we have a name, in the place of left_blank.
 				} else {