function validateForm()
{     

	
	var txtName = document.getElementById("u_name");
	var txtStreet = document.getElementById("u_street");
	var txtHouseNumber0 = document.getElementById("u_house_number0");
	var txtHouseNumber1 = document.getElementById("u_house_number1");
	var txtCity = document.getElementById("u_city");
	var txtCode0 = document.getElementById("u_code0");
	var txtCode1 = document.getElementById("u_code1");



	var isValid = true;
	
	
	if (txtName.value === "") {
		isValid = false;
	}
	
	if (txtStreet.value === "") {
		isValid = false;
	}
	
	if (txtHouseNumber0.value === "" && txtHouseNumber1.value === "") {
		isValid = false;
	}
	
	if (txtCity.value === "") {
		isValid = false;
	}
	
	if (txtCode0.value === "" || txtCode1.value === "") {
		isValid = false;
	}
	
	if(isValid){
		document.getElementById("form_error").innerHTML = '';
	}else{
		document.getElementById("form_error").innerHTML = 'Wypełnij poprawnie wszystkie pola.';
	}
	
	
	return isValid;


}