In the Insert/Modify Frame dialog box, enter a name of a frame you want to insert into your frame set. You can also modify a name of an existing frame and set a frame Size and Size Type using this dialog.

There are three Size Types of frames: %, Pixel, and Auto.

%. The percentage (%) option divides a current frame by  percentages specified in the Size control box.

Pixel. The Pixel option permits you to set an unchangeable size in pixels for a defined frame. If there is not enough space for the frame, it is resized to fit.

Auto. The Auto option sets a new frame size to the remaining space of a window.