function replaceImg(i) {
	imgResult = document[i].src.split("images/");
	
	if (imgResult[1] == 'arrow1.gif') {
		document[i].src = 'images/arrow2.gif';
	} else {
		document[i].src = 'images/arrow1.gif';
	}
}
function swapShowHide(i) {
	imgResult = document[i].src.split("images/");
	
	if (imgResult[1] == 'show_opt.gif') {
		document[i].src = 'images/hide_opt.gif';
	} else {
		document[i].src = 'images/show_opt.gif';
	}
}
function selall(checknum, layernum) {
	
	if (document.getElementById)
	{
		for(i=0; i < checknum; i++)
		{
			var chk = document.getElementById('cb' + layernum + '_' + i);
			chk.checked = true;
		}
	}

}
function clearall(checknum, layernum) {
	
	if (document.getElementById)
	{
		for(i=0; i < checknum; i++)
		{
			var chk = document.getElementById('cb' + layernum + '_' + i);
			chk.checked = false;
		}
	}

}

function blocking(nr) {
	
	if (document.layers)
	{
		if (document.layers[nr].display == 'none') {
			current = (document.layers[nr].display == 'none') ? 'block' : 'block';
			document.layers[nr].display = current;
		} else {
			current = (document.layers[nr].display == 'none') ? 'none' : 'none';
			document.layers[nr].display = current;
		}
	}
	else if (document.all)
	{
		if (document.all[nr].style.display == 'none') {
			current = (document.all[nr].style.display == 'none') ? 'block' : 'block';
			document.all[nr].style.display = current;
		} else {
			current = (document.all[nr].style.display == 'none') ? 'none' : 'none';
			document.all[nr].style.display = current;
		}
	}
	else if (document.getElementById)
	{
		if (document.getElementById(nr).style.display == 'none') {
			vista = (document.getElementById(nr).style.display == 'none') ? 'block' : 'block';
			document.getElementById(nr).style.display = vista;
		} else {
			vista = (document.getElementById(nr).style.display == 'none') ? 'none' : 'none';
			document.getElementById(nr).style.display = vista;
		}
	}

}


function changeBox(n) {
	n.checked = (n.checked == true) ? false : true;
}