function showPdf(id, url) {
  document.getElementById('img_' + id).src = document.getElementById(id).style.display == 'none' ? url+'/btn_hidden_pdf.png' : url+'/btn_show_pdf.png';
  document.getElementById(id).style.display = document.getElementById(id).style.display == 'none' ? 'block' : 'none';
  
  return false;
}
function showImg(id, url) {
  document.getElementById('img_' + id).src = document.getElementById(id).style.display == 'none' ? url+'/btn_hidden_img.png' : url+'/btn_show_img.png';
  document.getElementById(id).style.display = document.getElementById(id).style.display == 'none' ? 'block' : 'none';
  
  return false;
}

function mark(id)
{
	var box = document.getElementById(id);
	if (box.checked)
	{
		box.checked = false;
	}
	else
	{
		box.checked = true;
	}
}

function confirmLink(theLink, message, bad)
{
	var is_confirmed = confirm(message);

	if (!is_confirmed) {
		theLink.href = bad;
		window.location= bad;
	}
	return is_confirmed;
}

/*________checked all _______*/
function checkAllFields(ref)
{
var chkAll = document.getElementById('checkAll');
var checks = document.getElementsByName('cid[]');
var removeButton = document.getElementById('removeChecked');
var boxLength = checks.length;
var allChecked = false;
var totalChecked = 0;
	if ( ref == 1 )
	{
		if ( chkAll.checked == true )
		{
			for ( i=0; i < boxLength; i++ )
			checks[i].checked = true;
		}
		else
		{
			for ( i=0; i < boxLength; i++ )
			checks[i].checked = false;
		}
	}
	else
	{
		for ( i=0; i < boxLength; i++ )
		{
			if ( checks[i].checked == true )
			{
			allChecked = true;
			continue;
			}
			else
			{
			allChecked = false;
			break;
			}
		}
		if ( allChecked == true )
		chkAll.checked = true;
		else
		chkAll.checked = false;
	}
	
	for ( j=0; j < boxLength; j++ )
	{
		if ( checks[j].checked == true )
		totalChecked++;
	}
	removeButton.value = "Remove ["+totalChecked+"] Selected";
}

/****************************
pro vyber typu polozky
*****************************/

function genSelectStatEnd(svetadil,edit)
{
	if (svetadil > 0)
	{
		if (!send_xmlhttprequest(genSelectStatEndObsluha, 'GET', 'ajax/selectStat.php?cid=' + svetadil + '&edit=' + edit))
		{
			return false;
		}
	}
	else
	{
		clearSelect('stat', 'Vyber parametr ...');
	}

	return false;
}
function genSelectStatEndObsluha(xmlhttp)
{
	if (xmlhttp.readyState == 4)
	{
		var staty = xmlhttp.responseXML.getElementsByTagName('stat');// z odezvy ziskam vsechny elementy stat z xml
		document.getElementById('stat').options.length = 0;
		document.getElementById('stat').options[0] = new Option("Vyber parametr ...", 0);

		var edit = xmlhttp.responseXML.getElementsByTagName('edit');
		var sid = edit[0].firstChild.data;

		var index_v_selectu = 0;

		for (t = 0; t < staty.length; t++)
		{
			document.getElementById('stat').options[t+1] = new Option(staty[t].firstChild.data, staty[t].getAttribute('sid'));
			if (staty[t].getAttribute('sid') == sid)
			{
				index_v_selectu = t+1;
			}
		}

		document.getElementById('stat').selectedIndex = index_v_selectu;
	}
}

/*
zakladni funkce, ktera zajistuje komunikaci se serverem
*/
function send_xmlhttprequest(obsluha, method, url, content, headers)
{
	var xmlhttp = (window.XMLHttpRequest ? new XMLHttpRequest : (window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : false));
	if (!xmlhttp)
	{
		return false;
	}
	xmlhttp.open(method, url);
	xmlhttp.onreadystatechange = function() { obsluha(xmlhttp); };
	if (headers)
	{
		for (var key in headers)
		{
			xmlhttp.setRequestHeader(key, headers[key]);
		}
	}
	xmlhttp.send(content);
	return true;
}