function validate_required(field) 
{
	if (document.getElementById(field).value==null||document.getElementById(field).value==""||document.getElementById(field).value=="Add your comment...") 
	{
		return false;
	}
	else 
	{
		return true;
	}
}

function validate_email(field) 
{
	if (document.getElementById(field).value==null||document.getElementById(field).value=="")
	{
		return true;
	}
	else
	{
		apos=document.getElementById(field).value.indexOf("@")
		dotpos=document.getElementById(field).value.lastIndexOf(".")
		if (apos<1||dotpos-apos<2) 
		{
			return false;
		} 
		else 
		{
			return true;
		}
	}
}

function validate_form(code) 
{
	if (validate_required('commentname')==false) 
	{
		tooltip.show('Please enter your name or nickname','commentname');
		return false;
	}
	else if (validate_email('commentemail')==false) 
	{
		tooltip.show('E-mail address seems to be incorrect', 'commentemail');
		return false;
	}
	else if (validate_required('commentcontent')==false) 
	{
		tooltip.show('Please fill in the comment field', 'commentcontent');
		return false;
	}
	else if (document.getElementById('security_code').value<>code) 
	{
		tooltip.show('Incorrect security code', 'security_code');
		return false;
	}
	else
	{
		return true;
	}
}