function popup_open(i){
	
	var element = document.getElementById('news_'+i);
	var n=0;
	
	element.style.display = "block";

	function ligth(){
		n += 0.1;
		element.style.opacity = n;
		element.style.filter = "alpha(opacity="+n*100 + ")";
		if(n >= 1){
			clearInterval(Int);
		}
	}

	Int = setInterval(ligth,60);

}
var start = 0;
function popup_close(i){

	var element = document.getElementById('news_'+i);
	var n = 1;
	function ligth(){
		start = 1;
		n -= 0.1;
		element.style.opacity = n;
		element.style.filter = "alpha(opacity="+n*100 + ")";
		if(n <= 0){
			clearInterval(Int);
			element.style.display = "none";
			start = 0;
		}
	}
	
	if(start == 0){
		Int = setInterval(ligth,60);
	}
	//alert(start);
/*
  	element.style.display = "none";
  	element.style.opacity = 0;
	element.style.filter = "alpha(opacity=0)";
*/
}

function act_open(id){
	
	var part_element = document.getElementById('actual_part_'+id);
	var all_element  = document.getElementById('actual_'+id);
	
	part_element.style.display = "none";
	all_element.style.display = "block";

}

function act_close(id){
	
	var part_element = document.getElementById('actual_part_'+id);
	var all_element  = document.getElementById('actual_'+id);
	
	part_element.style.display = "block";
	all_element.style.display = "none";

}

function ref_on(id){
	
	var element = document.getElementById('ref_hover_'+id);
	
	element.style.visibility = "visible";

}

function ref_off(id){
	
	var element = document.getElementById('ref_hover_'+id);
	
	element.style.visibility = "hidden";

}

function stat_dyn()
{

  var element = document.getElementById('page_type');
  
  var tar=document.getElementById('text_page').style;
	
  if( element.value == 'statické'){
  		tar.display = 'inline';
  }
  else{
  		tar.display = 'none';
  }
}

function isValidEmail(str) {
	return (str.indexOf(".") > 1) && (str.indexOf("@") > 0);
}
// Declaring required variables
var digits = "0123456789";
// non-digit characters which are allowed in phone numbers
var phoneNumberDelimiters = "()- ";
// characters which are allowed in international phone numbers
// (a leading + is OK)
var validWorldPhoneChars = phoneNumberDelimiters + "+";
// Minimum no of digits in an international phone no.
var minDigitsInIPhoneNumber = 10;

function isInteger(s)
{   var i;
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character is number.
        var c = s.charAt(i);
        if (((c < "0") || (c > "9"))) return false;
    }
    // All characters are numbers.
    return true;
}

function stripCharsInBag(s, bag)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not in bag, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (bag.indexOf(c) == -1) returnString += c;
    }
    return returnString;
}

function checkInternationalPhone(strPhone){
	s=stripCharsInBag(strPhone,validWorldPhoneChars);
	return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}

function isValidForm( form )
{
	var name = form.name.value;
	var surname = form.surname.value;
	var email = form.email.value;
	var phone = form.phone.value;
	var covernote = form.covernote.value;

	var err = "";
	
	if(name == "")
		err += "Musíte vyplnit jméno!\n";
	if(surname == "")
		err += "Musíte vyplnit příjmení!\n";
	if(isValidEmail( email ) == false)
			err += "Emailová adresa nemá správný formát!\n";
	if (checkInternationalPhone(phone)==false)
			err += "Telefoní číslo nemá správný formát!\n";
	if(covernote == "")
		err += "Musíte vyplnit Průvodni dopis !\n";
	// pokud je vse ok				
	if( err == "" ){
		return true;
	}
	else{
		alert( err );
		return false;
	}
}