function confirm_delete()
{
	var ret = window.confirm("Please confirm removal.");
		
	if(ret)
	{
		return true;
	}
	else
	{
		return false;
	}
}

function is_email(email)
{
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (filter.test(email))
		return true;
	else 
		return false;
}

function is_numeric(num)
{
	var regexp = new RegExp('[0-9]+');
	return regexp.test(num);
}