settimeout

[utofranz]

i've being trying to change the src of a img tag in order to create some kind of a sequence of images.

<script type="text/javascript">
var i=0;
function r() {
	i++;
	if(i==4){e=1;}
	var src = "img-" + e + ".jpg"; //images are sorted by number (img-1,img2...)
	this.src = src;
	setTimeout(r.call(this),2000);
	}
</script>
....
<input type="button"  onclick="r.call(document.getElementById('impar'));">
<div><img id="impar" src="" ></div>

the code seems to work, but runs too fast,setTimeout does't look to do anything. if I replace this with this code

<script type="text/javascript">
var i=0;
var f=null;
function r() {
	i++;
	if(i==4){e=1;}
	var src = "img-" + e + ".jpg"; 
	foo.src = src;
	setTimeout(r,2000);
	}
function init(a){
        f=a;
        r();
        }
</script>
....
<input type="button"  onclick="init(document.getElementById('impar'));">
<div><img id="impar" src="" ></div>

everything works fine.i know call is not the very right thing to been used, but i don't understand why setTimeout dosn't work. some clue?