The mouse can be used to either scroll the page or zoom to a rectangle. Initially, the mouse action is set to scroll the page. You can change the mouse action using the menu.
The menu contains commands to change the mouse action.
The menu is accessible from the application menu at the top of the screen and from the context menu. (Click the right mouse button on the image to bring up the context menu.)
When the mouse action is set to scroll, dragging the mouse on the page will move the page in the direction of the drag. To scroll with the mouse, click and drag the mouse anywhere within the page. The page will move in the direction that you drag, as if you were dragging the page. If you drag the mouse up, the page will move up in the window, revealing the contents that were hidden at the bottom of the page; if you drag the mouse down, the page will move down in the window, revealing the contents that were hidden at the top of the page.
When the mouse action is set to zoom, use the mouse to drag out a rectangle within the page. When you release the mouse, the zoom will be set so that the rectangle fills the window. To cancel the zoom operation, type any key before releasing the mouse button.