How to tell unity to do something if I push a button once

This maybe easy for you guys, but I cannot figure out how to make it so that when you push a button, the action is carried out even if the button is released.

    //attacking
if (attackready == true){
     if (Input.GetButtonDown("Fire1")){
            //moveDirection.y = jumpSpeed-8;
            //moveDirection.x = 15+sliding;
            sliding--;
            moveDirection = Vector2(15+sliding, jumpSpeed-8);
            if (sliding <=-16){
            sliding = 10;

            }
            }

    }   

Yes this is very messy looking, but this is what I have for a code so far. This is also a 2d-platformer so mind the vector2. What happens is that when I do hit fire1, instead of actually sliding like i intend, the character jumps to the position and sliding variable only goes down by one.

Thanks in advance.

Input.GetButton instead of Input.GetButtonDown