I have been having great trouble getting my sprite to jump. So far I have a section of code which with a single tap of "W" will send the sprite in a constant velocity upwards. I need to be able to make my sprite come back down to the ground a certain time or height after begining the jump. There is also a constant pull of velocity 2 on the sprite to simulate some kind of gravity.

// Walking = true when there is collision detected between the sprite and ground

if (Walking == true)
    if (keystate.IsKeyDown(Keys.W))
        {
            Jumping = true;
        }

if (Jumping == true)
    {
        spritePosition.Y -= 10;
    }

Any ideas and help would be appreciated but I'd prefer a modified version of my code posted if at all possible.