Click this button to set the Library Folder selected among the files and folders in the Listing as the new Active Library for this Project. To choose a new Active Library, select a folder icon among the current folder's contents and click the Select button. To open a folder, double-click it. To move to the folder enclosing this one, click to pop-up the title and release over its name. Click this button to close this dialog without setting a new Active Library.