function contactForm()
	{
	var objF = document.forms["contact_form"];
	if(objF["form_field[name]"].value == "")
		{
		if(lang == "cz"){alert("Vyplňte položku Jméno a příjmení!");}
		else{alert("You didn't fill your name!");}
		objF["form_field[name]"].focus();
		return false;
		}
	if(objF["form_field[phone]"].value == "")
		{
		if(lang == "cz"){alert("Vyplňte položku Telefon!");}
		else{alert("You didn't fill your phone!");}
		objF["form_field[phone]"].focus();
		return false;
		}
	if(objF["form_field[email]"].value == "")
		{
		if(lang == "cz"){alert("Vyplňte položku E-mail!");}
		else{alert("You didn't fill your e-mail!");}
		objF["form_field[email]"].focus();
		return false;
		}
	
	var str = objF['form_field[email]'].value;
	var filter = /^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i;
	if (!filter.test(str))
		{
		if(lang == "cz"){alert("E-mailová adresa je v neplatném formátu!");}
		else{alert("Invalid e-mail format!");}
		objF['form_field[email]'].focus();
		return false;
		}
	if(objF["form_field[message]"].value == "")
		{
		if(lang == "cz"){alert("Vyplňte položku Zpráva!");}
		else{alert("You didn't write any message!");}
		objF["form_field[message]"].focus();
		return false;
		}
	}