function HideLayer(lay) {
	if (ie4) {
			if (document.all[lay].style) {
				document.all[lay].style.visibility = "hidden";
				document.all[lay].style.display = 'none'
			}
			else if (document.all[lay].length) {
				for (i=0; i< document.all[lay].length; i++) {
					if (document.all[lay][i]) {
						document.all[lay][i].style.visibility = "hidden";
						document.all[lay][i].style.display = 'none'
					}
				}
			}
	}
	else if (ns4) {
		document.layers[lay].visibility = "hide";
	}
	else if (ns6) {
		document.getElementById(lay).style.visibility = 'hidden';
		document.getElementById(lay).style.display = "none";
	}
}

function IsHideLayer(lay) {
	if (ie4) {
		return document.all[lay].style.visibility == "hidden" || document.all[lay].style.display == "none";
	}
	else if (ns4) {return document.layers[lay].visibility == "hide";}
		else if (ns6) {
			 return document.getElementById(lay).style.display == "none" || document.getElementById(lay).style.visibility == "hidden";
		}
}

function ShowLayer(lay) {
	if (ie4) {
			if (document.all[lay].style) {
				document.all[lay].style.visibility = "visible";
				document.all[lay].style.display = ''
			}
			else if (document.all[lay].length) {
				for (i=0; i< document.all[lay].length; i++) {
					if (document.all[lay][i]) {
						document.all[lay][i].style.visibility = "visible";
						document.all[lay][i].style.display = ''
					}
					else
						break;
				}
			}
	}
	else if (ns4) {
			document.layers[lay].visibility = "show";
			document.layers[lay].style.display = '';
	}
	else if (ns6) {
		document.getElementById(lay).style.visibility = 'visible';
		document.getElementById(lay).style.display = '';
	}
}

function WriteToLayer(lay,txt) {
	if (ie4) {
		document.all[lay].innerHTML = txt;
	}
	if (ns4) {
		document[lay].document.write(txt);
		document[lay].document.close();
	}
	if (ns6) {
		over = document.getElementById(lay);
		range = document.createRange();
		range.setStartBefore(over);
		domfrag = range.createContextualFragment(txt);
		while (over.hasChildNodes()) {
			over.removeChild(over.lastChild);
		}
		over.appendChild(domfrag);
	}
}

function SwitchVisibility(layer) {
	if (IsHideLayer(layer)) {
		ShowLayer(layer);
	}
	else {
		HideLayer(layer);
	}
	return false;
}