function toggle( targetId ){
  if (document.getElementById){
  target = document.getElementById( targetId );
  if (target.style.display == "") {  target.style.display = "none"; }
  if (target.style.display == "none"){
    target.style.display = "block";
  } else {
    target.style.display = "none";
  }
  }  
  return true;
}



function prevedInt (a) { // prevede string na int
  a = parseInt(a);
  if (isNaN(a)) { a = 0; }
  return a;
}

function spocitejCelkovouCenu () { // prepocitava celkovou cenu ve formulari
  document.getElementById("CelkovaCena").value = 
  prevedInt(document.getElementById("DVDPrehravacCena").value) 
  + prevedInt(document.getElementById("AVPrijimacCena").value)
  + prevedInt(document.getElementById("ReprosoustavyCena").value)
  + prevedInt(document.getElementById("ReprodukceObrazuTVCena").value)
  + prevedInt(document.getElementById("ReprodukceObrazuLCDCena").value)
  + prevedInt(document.getElementById("ReprodukceObrazuProjektorCena").value)
  + prevedInt(document.getElementById("JinyPristrojCena").value)  
  + prevedInt(document.getElementById("VseVJednomCena").value)    
  ;
  if (document.getElementById("CelkovaCena").value == "0") {
    document.getElementById("CelkovaCena").value = "";
  } 
}


function changeCSS(myclass,element,value) {  // meni hodnotu v konkretni tride css
  var CSSRules
  if (document.all) {
    CSSRules = 'rules'
  }
  else if (document.getElementById) {
    CSSRules = 'cssRules'
  }
  for (var i = 0; i < document.styleSheets[0][CSSRules].length; i++) {
    if (document.styleSheets[0][CSSRules][i].selectorText == myclass) {
    document.styleSheets[0][CSSRules][i].style[element] = value
    }
  }
}	

function formSetRow(formAnchor, formCena, option) { // nastavuje radek formulare - zapnuty / vypnuty
  if (option == "on") {
	document.getElementById(formCena).disabled = false;
	// document.getElementById(formAnchor).disabled = false;
	document.getElementById(formAnchor).style.visibility = "visible";
	document.getElementById(formCena).style.background = "white";			
}
 if (option == "off") {	
	document.getElementById(formCena).disabled = true;
	// document.getElementById(formAnchor).disabled = true;
	document.getElementById(formAnchor).style.visibility = "hidden";	
	document.getElementById(formCena).style.background = "transparent";	  
}
} 
	
function formChangeRow(formAnchor, formCena, formVlastnosti) { // meni stav radku formulare
	document.getElementById(formCena).disabled = !document.getElementById(formCena).disabled;  	
	// document.getElementById(formAnchor).disabled = !document.getElementById(formAnchor).disabled;
	if (document.getElementById(formCena).disabled) {
	document.getElementById(formCena).style.background = "transparent";
	document.getElementById(formCena).value = "";	// prepocitani ceny
	spocitejCelkovouCenu();									// prepocitani ceny
	document.getElementById(formAnchor).style.visibility = "hidden";	
	document.getElementById(formVlastnosti).style.display = "none";	
	}
	else {
	document.getElementById(formCena).style.background = "white";	
	document.getElementById(formAnchor).style.visibility = "visible";	
	}	
} 
	
function formInit() { // inicializuje formular
  changeCSS(".vlastnosti","display","none");
  formSetRow("DVDLink", "DVDPrehravacCena", "off");
  formSetRow("AVLink", "AVPrijimacCena", "off");
  formSetRow("ReproLink", "ReprosoustavyCena", "off");
  formSetRow("VseLink", "VseVJednomCena", "off");
  formSetRow("ReprodukceObrazuTVLink", "ReprodukceObrazuTVCena", "off");	
  formSetRow("ReprodukceObrazuLCDLink", "ReprodukceObrazuLCDCena", "off");	
  formSetRow("ReprodukceObrazuProjektorLink", "ReprodukceObrazuProjektorCena", "off");
  formSetRow("JinyPristrojLink", "JinyPristrojCena", "off");
}