Computer mouse

A computer mouse comprising:

• an upper shell;
• a first button pivotably mounted to a side of the upper shell, wherein the first button is operable of pivoting inwards relative to the upper shell to activate a first key function of a keyboard;
• and
• a second button;
• wherein the upper shell comprises a top plate, a first side plate extends down from a first side of the top plate, and defines a first opening, two first blocks protrude from an inner surface of the first side plate at top and bottom sides of a rear end of the first opening, the first button is pivotably mounted to the two first blocks;
• wherein a second side plate extends down from a second side of the top plate opposite to the first side, the second button comprises a first plate, a second plate opposite to the first plate, and a supporting plate perpendicularly connected between the first and second plates, an engaging portion is formed at a rear end of the first plate, two posts perpendicularly protrude from top and bottom ends of the engaging portion, two second blocks protrude from an inner surface of the second side plate at top and bottom sides of a rear ends of the second opening, the two second blocks each defines a second pivot slot, the two posts rotatably engage in the two second pivot slots;
• wherein the first plate is longer than the second plate, the second plate locates inside the upper shell, the first plate covers the second opening;
• wherein an inset portion is formed in a front end of the second opening, a front end of the first plate resists against an outer surface of the inset portion;
• and
• wherein a depressed semicircular avoiding groove is defined in the second side plate, adjacent to the inset portion, an operating portion protrudes from a front end of the first plate, and faces the avoiding groove.