/* Hlídá max. délku pole textarei. */
function keepTextareaLength(inputid, maxLength) {

	var box = document.getElementById(inputid);
	var length = box.value.length;
	if (length > maxLength)
		box.value = box.value.substring(0, maxLength);
}

function openPagePreviewWindow(url) {

	return window.open(url, 'preview', 'left=100,top=100,width=1024,height=768,toolbar=no,menubar=yes,location=yes,resizable=yes,scrollbars=yes');
}

function browser_isIE() {

	return navigator.appName.indexOf("Microsoft") != -1;
}

function getWindowScrollTop() {

	var fromTop					= document.body.scrollTop;
	if (fromTop == null || fromTop == 0) {
		if (window.pageYOffset)
			fromTop				= window.pageYOffset;
		else if (document.body.parentElement && document.body.parentElement.scrollTop)
			fromTop				= document.body.parentElement.scrollTop;
	}
	
	return fromTop;
}