Size of Search pane/box

[beethoven]

I am using two horizontal panes for files and folders and underneath have the search pane/box where you can enter your search criteria. Somehow I must have accidentally hit some short key and the search box is now taking up half the full page. While I can find the little blue arrow to make it small again, I cannot find a setting to reduce the size of this box when open (ie when name & location, date or tag options are shown). I can increase and reduce the size of the top pane but the lower pane seems stuck against the opened search pane unwilling to extend downwards. I am sure this is probably just a simple ctrl + something but I am stuck. Any suggestions?

[jupe]

Alt+F12

[beethoven]

Jupe - thank you very much