How to retrieve the blank space on tool bar to search for pages or information.

I used to have a blank space on the tool bar where I could search for new pages or information. Trying to find and reinstall on "Customize the Toolbar" was not successful. I have 13 items on the toolbar, and at times going to the >> would open a space to type my search. Now does not work. What do I need to do to have it back. I have not added more items to the tool bar. This space seems to have disappeared. Thanks in advance for your help to resolve this issue.

James