var dx=10; dy=10; t=1; xmax=500; ymax=475; delta=10;
//var x=parseInt(document.getElementById('boxframe').style.width);
//var y=parseInt(document.getElementById('boxframe').style.height);
var x=5; y=5;
function sposta(){
		
		if(x+dx>=xmax) x=xmax;
		else x=x+delta*dx;
		
		if(y+dy>=ymax) y=ymax;
		else y=y+dy;
		
		//if(x>=xmax && y>=ymax) {clearsetInterval(temp);}

		//x=x+delta*dx;
		//y=y+dy
		
		//x=x+dx;
		//y=y+20*Math.sin(x/10);
document.getElementById('boxframe').style.width=x+dx;
document.getElementById('boxframe').style.height=y+dy;
		}
var temp=setInterval('sposta()',t);