1. A method for recognizing a gesture input on a display screen for a computer system, the method comprising the steps of: receiving a stroke input by a user onto a computer screen, the stroke being represented as a string of points; smoothing said stroke by reducing the number of points that represent the stroke such that the points of the smoothed stroke are located at least a threshold distance apart from one another; calculating angles between adjacent segments of said smoothed stroke and calculating derivatives of said angles; and determining whether said stroke substantially represents an ellipse, the ellipse determining step utilizing said angles and said derivatives of said angles to determine whether said stroke substantially curves in one direction or curves in more than one direction, wherein said stroke is not considered to substantially represent an ellipse when said stroke does not curve in one direction, and summing said derivatives of said angles and checking whether said sum is within a predetermined range of values, wherein said stroke is not considered to substantially represent an ellipse when said sum is outside said range of values.