var done = 0;
var step=1;
var yp;
var addtop=0;
var txttop=140;
function scroll(){
	if(document.layers){		
		document.layers["txt"].top=txttop+addtop-yp;
		}
 	else{		
		document.all["txt"].style.top=txttop+addtop-yp;
		}
	yp=yp+step;
	if((yp-addtop)>255){
		addtop=0;
		//Restaura la posicion original
		if(document.layers){
			document.layers["txt"].top=txttop+addtop;
			}
		else{
			document.all["txt"].style.top=txttop+addtop;
			}
		yp=0;
	}
 	setTimeout('scroll()', 35);

}
function ActivateScroll(){
 	if(done) return;
	done = 1;
	yp=0;
	scroll();

}