function check_form(the_form)
{
	var the_name     = the_form.name.value;
	var the_email    = the_form.email.value;
	var the_url_site  = the_form.url_site.value;
	var the_site_name  = the_form.site_name.value;
	var the_url_logo = the_form.url_logo.value;
	var the_sc = the_form.sc.value;
				
	if ( the_name == '' )
	{
		alert("Ban chua nhap ten ban !");
		the_form.name.focus();
		return false;
	}
			
	if ( the_email == '' )
	{
		alert("Ban chua nhap dia chi thu !");
		the_form.email.focus();
		return false;
	}
	if ( the_site_name == '' )
	{
		alert("Ban chua nhap ten site !");
		the_form.site_name.focus();
		return false;
	}
	
	if ( the_url_site == '' )
	{
		alert("Ban chua nhap dia chi site !");
		the_form.url_site.focus();
		return false;
	}
	
	if ( the_url_logo == '' )
	{
		alert("Ban chua nhap dia chi logo !");
		the_form.url_logo.focus();
		return false;
	}
	
	if ( (the_sc == '') )
	{
		alert("Ban chua nhap ma so an toan !");
		the_form.sc.focus();
		return false;
	}

	var the_at    = the_email.indexOf("@");
	var the_dot   = the_email.indexOf(".");
	var the_space = the_email.indexOf(" ");

	if ( (the_at!=-1)&&(the_at!=0)&&(the_dot!=-1)&&(the_dot>the_at + 1)&&(the_dot<email.length-1)&&(the_space==-1) )
	return true;
	alert("Email khong hop le");
	the_form.email.focus();
	return false;
}