var povinne_barva = "#FAFF68"


function validate(formular)
{
    var phone=formular.txtPhone
	
  	if ((formular.phone.value==null)||(formular.phone.value=="")){
  		alert("Vyplňte telefonní číslo.");
  		formular.phone.focus();
  		formular.phone.style.backgroundColor=povinne_barva;
  		return false;
  	}
  	if (checkInternationalPhone(formular.phone.value)==false){
  		alert("Vyplňte prosím správný formát telefonního čísla včetně předvolby\n\n např.: +420777112233");
  		formular.phone.value="";
  		formular.phone.focus();
  		formular.phone.style.backgroundColor=povinne_barva;
  		return false;
  	}
    if (formular.jmeno.value=="")
    {
        alert("Vyplňte prosím Vaše jméno");
        formular.jmeno.focus();
        formular.jmeno.style.backgroundColor=povinne_barva;
        return false;
    }
    else if (formular.prijmeni.value=="")
    {
        alert("Vyplňte prosím Vaše příjmení");
        formular.prijmeni.focus();
        formular.prijmeni.style.backgroundColor=povinne_barva;
        return false;
    }
    else if (formular.zprava.value == "")
    {
        alert("Pokud nám chcete napsat, neměli byste posílat prázdný formulář!");
        formular.zprava.focus();
        formular.zprava.style.backgroundColor=povinne_barva;
        return false;
    }    
    else if (formular.email.value != "")
    {
        var re = new RegExp("^[^.]+(\.[^.]+)*@([^.]+[.])+[a-z]{2,4}$");
        if (!re.test(formular.email.value))
        {
            alert("Zadali jste neplatný formát Vašeho emailu!");
            formular.email.focus();
		        formular.email.style.backgroundColor=povinne_barva;
            return false;
        }
    }        
    else
      return true;
}

/**
 * DHTML phone number validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */

// 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 trim(s)
{   var i;
    var returnString = "";
    // Search through string's characters one by one.
    // If character is not a whitespace, append to returnString.
    for (i = 0; i < s.length; i++)
    {   
        // Check that current character isn't whitespace.
        var c = s.charAt(i);
        if (c != " ") returnString += c;
    }
    return returnString;
}
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){
var bracket=3
strPhone=trim(strPhone)
if(strPhone.indexOf("+")>1) return false
if(strPhone.indexOf("-")!=-1)bracket=bracket+1
if(strPhone.indexOf("(")!=-1 && strPhone.indexOf("(")>bracket)return false
var brchr=strPhone.indexOf("(")
if(strPhone.indexOf("(")!=-1 && strPhone.charAt(brchr+2)!=")")return false
if(strPhone.indexOf("(")==-1 && strPhone.indexOf(")")!=-1)return false
s=stripCharsInBag(strPhone,validWorldPhoneChars);
return (isInteger(s) && s.length >= minDigitsInIPhoneNumber);
}