Locking an element disables the option to move or re-size it.
This can be used to make working with a number of elements in a single area easier or to prevent mistakes.
To lock an element:
1. Drag the element to the desired position
2. Click the Lock icon located on the element's settings menu and then click the Lock button in the dialogue box that will appear.
Note that the Lock icon is now active meaning that the element is locked.
3. To unlock an element, click the Lock button again
