function showPopup() {
	var el = document.getElementById('popupDiv');
	var elRest = document.getElementById('nopopupDiv');
	el.style.display = 'block';
//	elRest.style.display = 'none';
	positionPopup();
}

function hidePopup() {
	var el = document.getElementById('popupDiv');
	var elRest = document.getElementById('nopopupDiv');	
	el.style.display = 'none';
//	elRest.style.display = 'block';
	enableSelects();
}

function positionPopup() {
	var el = document.getElementById('popupDiv');
	var spacingWidth = 15;
	var spacingHeight = 15;
	var borderWidth = 5;
	el.style.width = (getViewportWidth() - (2 * spacingWidth) - (2 * borderWidth)) + 'px';
	el.style.height = (getViewportHeight() - (2 * spacingHeight) - (2 * borderWidth)) + 'px';
	el.style.top = spacingHeight + 'px';
	el.style.left = spacingWidth + 'px';
}

function imagePopup(imageUrl) {
	disableSelects();
	showPopup();
	var el = document.getElementById('popupDiv');
	el.innerHTML  = '<img src="' + imageUrl + '" alt="click om te sluiten" style="cursor: pointer;" onclick="hidePopup();" />';	
}

var selectAr = new Array();

function disableSelects() {
	if (selectAr.length != 0) {
		return;
	}
	var selectEls = document.getElementsByTagName('select');
	var selectEl;
	var tel;
	
	for (tel in selectEls) {
		selectEl = selectEls[tel];
		if ((selectEl.style != undefined) && (selectEl.style.visibility != 'hidden')) {
			selectEl.style.visibility = 'hidden';
			selectAr.push(selectEl);
		}
	}
}

function enableSelects() {
	if (selectAr.length == 0) {
		return;
	}
	
	var selectEl;
	var tel;
	
	for (tel in selectAr) {
		selectEl = selectAr[tel];
		if (selectEl.style.visibility == 'hidden') {
			selectEl.style.visibility = 'visible';
		}
	}
	
	selectAr = new Array();
}