function clcInit() {

	smax = 30
	ssnum = 0;

	with (document) {
		writeln("<div>");
		writeln("<input id='add' type='button' onclick='insertSegment(); enumSegment();' value='Přidat' />");
		writeln("<input id='del' disabled type='button' onclick='removeSegment(); enumSegment();' value='Ubrat'>");
		writeln("<input id='add' type='button' onclick='enumSegment();' style='font-weight:bold;' value='Přepočítat'>");
		writeln("</div>");

		for (i=0; i<smax; i++) {
			writeln("<div class='segment' id='s"+i+"'>");

			//writeln("<big><b>"+(i+1)+")</b></big>");

			writeln("<nobr>");
			writeln("<b>objem nádoby =</b>");
			writeln("<select id='objem"+i+"' onchange='enumSegment()'>");
			writeln("<option value='60'>60 litrů</option>");
			writeln("<option value='110'>110 litrů</option>");
			writeln("<option value='120'>120 litrů</option>");
			writeln("<option value='140'>140 litrů</option>");
			writeln("<option value='240'>240 litrů</option>");
			writeln("<option value='1100'>1100 litrů</option>");
			writeln("</select>")
			writeln("</nobr><br />");

			writeln("<nobr>");
			writeln("<b>počet nádob =</b>");
			writeln("<input id='kusy"+i+"' type='text' maxlength='2' size='2' value='0' onchange=\"testInt('kusy"+i+"',1); enumSegment()\" />");
			writeln("</nobr><br />");

			writeln("<nobr>");
			writeln("<b>frekvence svozu =</b>");
			writeln("<select id='frekvence"+i+"' onchange='enumSegment()'>");
			writeln("<option value='1.0'>1&times; týdně</option>");
			writeln("<option value='2.0'>2&times; týdně</option>");
			writeln("<option value='3.0'>3&times; týdně</option>");
			writeln("<option value='4.0'>4&times; týdně</option>");
			writeln("<option value='5.0'>5&times; týdně</option>");
			writeln("<option value='0.5'>1&times; za 14 dní</option>");
			writeln("</select>")
			writeln("</nobr><br />");

			writeln("<nobr>");
			writeln("<b>počet týdnů =</b>");
			writeln("<input id='tydny"+i+"' type='text' maxlength='2' size='2' value='52' onchange=\"testInt('tydny"+i+"',52); enumSegment()\" />");
			writeln("</nobr><br />");

			writeln("<nobr>");
			writeln("<b>předpokládané množství odpadu v dodávce* =</b>");
			writeln("<span class='result' id='mndod"+i+"'>0 kg</span>");
			writeln("</nobr><br />");
			
			writeln("<nobr>");
			writeln("<b>předpokládané množství odpadu za rok** =</b>");
			writeln("<span class='result' id='mnrok"+i+"'>0 kg</span>");
			writeln("</nobr><br />");
			
			
			writeln("</div>");
		}

		writeln("<div style='text-align:right;width:360px;'><nobr><big><b>Celková hmotnost za dané období = </b></big><span class='result' id='mnsum'>0 kg</span></nobr><br /></div>");
		
	}

	showSegments(ssnum);

}

function enumSegment() {

	var mnsum = 0;
	
	for (num=0; num<=ssnum; num++) {
		var koef = 0.083816434;
		var kusy = findObj("kusy"+num).value;
		var objem = findObj("objem"+num).value;
		var frekvence = findObj("frekvence"+num).value;
		var tydny = findObj("tydny"+num).value;

		var mndod = Math.ceil(kusy * objem * koef / 10.0) * 10.0;
		var mnrok = Math.ceil(kusy * objem * frekvence * tydny * koef / 100.0) * 100.0;

		findObj("mndod"+num).innerHTML = mndod + " kg";
		findObj("mnrok"+num).innerHTML = mnrok + " kg";

		mnsum += mnrok; 
	}
	findObj("mnsum").innerHTML = mnsum + " kg";
}



function insertSegment() {
	ssnum++;
	showSegments(ssnum);
	findObj("add").disabled = (ssnum+1>=smax);
	findObj("del").disabled = (ssnum-1<0);
}

function removeSegment() {
	ssnum--;
	hideSegments(ssnum);
	findObj("del").disabled = (ssnum-1<0);
	findObj("add").disabled = (ssnum+1>=smax);
}

function showSegments(to) {
	for (i=0; i<=to; i++) {	
		obj = findObj("s"+i);
		obj.style.display = "block";
	}
}

function hideSegments(from) {
	for (i=from+1; i<smax; i++) {	
		obj = findObj("s"+i);
		obj.style.display = "none";
	}
}

function findObj(objName) {
	if (!(obj = document[objName]) && document.all) { 
		obj = document.all[objName]; 
	}
	else {
		obj = document.getElementById(objName);
	}
	return obj;
}

function testInt(name, def) {
   var obj = findObj(name);
   var sText = obj.value;
   var ValidChars = "0123456789";
   var IsNumber=true;
   var Char;

   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         IsNumber = false;
		 obj.value = def;
         }
      }
   return IsNumber;
}