The New Project returns the project options to their
default values (the same as when you start Glade without providing
it a project file name). You will be asked to confirm that you wish to
start a new project. Be sure you have saved the current project (if
there is one) before you start a new project. Click the
Cancel button on the popup if you have not yet saved the
current project and wish to do so. Then choose New
Project again. Click on the OK button to proceed.