//<![CDATA[
	function ref (elstringid) {
		if (document.all) return document.all[elstringid]; 
		else
		if (document.getElementById) return document.getElementById(elstringid);
	}

	function poc() {
		if (ref("doba").value <= 0)
			ref("doba").value='0';
		ref("splatka").value=Math.round(((ref("uver_h").value*(ref("urok_h").value/1200))/(1-(Math.pow((1/(1+(ref("urok_h").value/1200))),(ref("doba").value*12))))));
		if (isNaN(ref("splatka").value))
			ref("splatka").value='0';
	}
	function zup() {
		if (ref("uver").value <= 0)
			ref("uver").value='0';
		var str;
		str = ref("uver").value;
		ref("uver_h").value = str.replace(",",".");
		ref("splatka").value=Math.round(((ref("uver_h").value*(ref("urok_h").value/1200))/(1-(Math.pow((1/(1+(ref("urok_h").value/1200))),(ref("doba").value*12))))));
		if (isNaN(ref("splatka").value))
			ref("splatka").value='0';
	}
	function prep() {
		if (ref("urok").value <= 0)
			ref("urok").value='0';
		var str;
		str = ref("urok").value;
		ref("urok_h").value = str.replace(",","."); 
		ref("splatka").value=Math.round(((ref("uver_h").value*(ref("urok_h").value/1200))/(1-(Math.pow((1/(1+(ref("urok_h").value/1200))),(ref("doba").value*12))))));
		if (isNaN(ref("splatka").value))
			ref("splatka").value='0';
	}
//]]>