function check_form(obj)
{
	var keyword = obj.keyword.value;
	if (!keyword)
	{
		alert("Oooooooooh! Please input a keyword");
		return false;
	}
	return true;
}

function check_comment(obj)
{
	var name = $.trim(obj.name.value);
	var email = $.trim(obj.email.value);
	var contents = $.trim(obj.contents.value);

	if ( !name )
	{
		obj.name.focus();
		alert("Your name?");
		return false;
	}
	if (!check_email(email))
	{
		alert("Email is wrong!");
		return false;
	}

	if ( !contents )
	{
		obj.name.focus();
		alert("Your talk is empty...");
		return false;
	}
}

function check_email(v)
{
	if ( v.length == 0 ) return;
	return isEmail(v);
}

function isEmail(str)
{
	var par = /^[0-9a-zA-Z_.-]+@[0-9a-zA-Z-]+\.([a-zA-Z]{2,4}|[0-9a-zA-Z-]+\.[a-zA-Z]{2,4})$/;
	return (str.search(par)==0);
}