clicking and attacking different animations

hi

i am trying to make it so that eachtime i get input.mouse(0), it uses slash a and then the second time i click mouse it does slash b and the third time it does slash c, then the loop resets to slash a again(kind of like a hack and slash game type of attacking). its kinda of confusing i know and i know i havent shown my code , this is because i dont know where to start with this type of thing.

plz dont critisize, i m just a guy askin for some help. any suggestion help

var movement : int = 1;

function Update(){
    If (Input.GetButtonDown("Fire1")){

        if(movement==1){
            animation.Play("Slash1");
        }else
        if(movement==2){
            animation.Play("Slash2");
        }else
        if(movement==3){
            animation.Play("Slash3");
        }

        if(movement==3){
            movement=1;
        }else{
            movement+=1;
        }

    }

}