Names with apostrophe's

Hello, I could use some help here. I have an entry in the MySQL, that use an apostrophe, for example lets call it "O'Reilly". I have added addslashes to my insert statement so MySQL accepts it with out complaining. The problem I am having is I use this information "O'Reilly" in a GET URL somewhere else in the site. For example here's my link: echo("<td><a href='user_book_results_detail.php?book=$row[book]>$row[book]</a></td>"); When I mouse over and view the URL, PHP thinks the apostrophe (single quote) is the end and quits. I know I need to include a back slash or escape this character but I am not entirely sure how I do it? Suggestions? Sample URL: http://user_book_results_detail.php?book=O