$i = 1;
function changeTxt($j) {
	$boxId = "boxtxt";
	$linkId = "linktxt";
	if ($j != $i) {
		document.getElementById($boxId + $i).style.display = "none";
		document.getElementById($boxId + $j).style.display = "block";
		document.getElementById($linkId + $i).className = "";
		document.getElementById($linkId + $j).className = "active";				
	}
	$i = $j;
}