function call_backForm()
{
	if(document.forms[0].name.value == "")
	{
		alert("Vul uw naam in, svp.");
		document.forms[0].name.focus();
		document.forms[0].name.select();
	}
	else if(document.forms[0].phone.value == "")
	{
		alert("Vul uw telefoonnummer in, svp.");
		document.forms[0].phone.focus();
		document.forms[0].phone.select();
	}
	else
	{
	document.forms[0].submit();
	}
}