questa è la versione funzionante e corretta della classe...se a qualcuno servisse per delle modifiche eccola...
Codice PHP:
function Slider(cosa){
this.vel = 1;
this.mov = 1;
this.id = cosa;
this.start = 100-document.getElementById(this.id).offsetHeight;
var scope = this;
this.end = this.start+document.getElementById(this.id).offsetHeight;
document.getElementById(this.id).style.top=this.start+"px";
function getPosition(){
return parseInt(document.getElementById(scope.id).style.top);
};
function scendilo(){
document.getElementById(scope.id).style.top = getPosition() + scope.mov + "px";
if (getPosition() >= scope.end) clearInterval(timeout);
};
function salilo(){
document.getElementById(scope.id).style.top = getPosition() - scope.mov + "px";
if (getPosition() <= scope.start) clearInterval(timeout);
};
this.move = function(){
if (getPosition() == this.start) timeout = setInterval(scendilo, scope.vel);
else timeout = setInterval(salilo, scope.vel);
}
}