// validacija eMail-Adrese
function isValidEmail(email, required) {
	// regexp za email adresu
	var regexpForEmail = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*[.][a-zA-Z]{2,4}$/
	
    if (required==undefined) {   // if not specified, assume it's required
        required=true;
    }
    if (email==null) {
        if (required) {
            return false;
        } else {
			return true;
		}
    }
    if (email.length==0) {  
        if (required) {
            return false;
        } else {
			return true;
		}
    }

	return email.match(regexpForEmail);
}