3. The method of claim 2 , wherein displaying the first gripper and the second gripper comprises: determining a width of the first gripper and the second gripper based on display screen parameters.
2. The method of claim 1 , wherein the display screen is a touch screen, and wherein the method further comprises: displaying a first gripper at a first gripper location associated with the beginning location; and displaying a second gripper at a second gripper location associated with the ending location.