function checkRequired() {
	var polozky = document.getElementsByTagName("input");
	var vyplnene = 1;
	var nastav_focus = -1;
	
	if(polozky!=null)
	{
		if(polozky.length!=null)
		{
			for(i=0;i<polozky.length;i++)
			{
				if(polozky[i].getAttribute("required")!=null)
				{
					if(isEmpty(polozky[i].value))
					//if (polozky[i].value == '')
					{
						vyplnene = 0;
						polozky[i].style.backgroundColor = "#ee1034";
						polozky[i].style.color = "#ffffff";
						if(nastav_focus == -1)
						{
							nastav_focus = i;
						}
					}
					else
					{
						polozky[i].style.backgroundColor = "";
						polozky[i].style.color = "";
					}
				}
			}
		}
		else
		{
			if(polozky.getAttribute("required")!=null)
			{
				if(isEmpty(polozky.value))
				{
					vyplnene = 0;
					polozky.style.backgroundColor = "#ee1034";
					polozky.style.color = "#ffffff";
					if(nastav_focus == -1)
					{
						nastav_focus = i;
					}
				}
				else
				{
					polozky.style.backgroundColor = "";
					polozky.style.color = "";
				}
			}
		}
	}		
	
	if(vyplnene == 0)
	{
		if(nastav_focus != -1)
		{
		    alert("Nevyplnili ste povinné položky.");
			polozky[nastav_focus].focus();
		}
		return false;
	}
	else
		return true;
}