var IE = document.all?true:false;

function f_clientHeight() {
	return f_filterResults (
		window.innerHeight ? window.innerHeight : 0,
		document.documentElement ? document.documentElement.clientHeight : 0,
		document.body ? document.body.clientHeight : 0
	);
}

function f_filterResults(n_win, n_docel, n_body) {
	var n_result = n_win ? n_win : 0;
	if (n_docel && (!n_result || (n_result > n_docel)))
		n_result = n_docel;
	return n_body && (!n_result || (n_result > n_body)) ? n_body : n_result;
}

function f_scrollTop() {
	return f_filterResults (
		window.pageYOffset ? window.pageYOffset : 0,
		document.documentElement ? document.documentElement.scrollTop : 0,
		document.body ? document.body.scrollTop : 0
	);
}

function pv_showLarge(image, _width, _height) {

	var _body = document.getElementsByTagName("body")[0];
	if (IE) {
		noScrollIE();
	} else {
		_body.style.overflow = "hidden";
	}

	var _layer = document.createElement('div');
	_layer.id = "photoviewer_overlay";
	_layer.style.top = f_scrollTop() + 'px';

	var _popup = document.createElement('div');
	_popup.id = "photoviewer_popup";

	var _image = document.createElement('img');
	_image.id = "photoviewer_image";
	_image.src = image.src.substr(0,image.src.length - 6) + '.normal';

	var _closebutton = document.createElement('div');
	_closebutton.id = "photoviewer_closebutton";
	_closebutton.onclick = function(e) { pv_removeDiv(this.parentNode.parentNode) };

	var _textdiv = document.createElement('div');
	_textdiv.id = "photoviewer_textdiv";

	var _text = document.createElement('a');
	_text.href = 'download.php?f=' + image.src.substr(0,image.src.length - 6);
	_text.innerHTML = "grote foto";

	_textdiv.appendChild(_text);
	_popup.appendChild(_image);
	_popup.appendChild(_closebutton);
	_popup.appendChild(_textdiv);
	_layer.appendChild(_popup)
	_body.appendChild(_layer);

	_image.style.width = _width + 'px';
	_image.style.height = _height + 'px';

	_popup.style.width = _width + 6 + 'px';
	_popup.style.height = _height + 35 + 'px';
	_popup.style.marginLeft = ((_width + 6) / 2) * -1 + 'px';
	_popup.style.marginTop = ((_height + 40) / 2) * -1 + 'px';
}

function pv_removeDiv(div) {
	var _body = document.getElementsByTagName("body")[0];
	_body.removeChild(div);
	if (IE) {
		scrollIE();
	} else {
		_body.style.overflow = "auto";
	}
}

function noScrollIE() {
	document.body.scroll="no";
}

function scrollIE() {
	document.body.scroll="yes";
}