function grayoutFields()
{
	var optional_table = document.getElementById('table_optional');
	var allElements = optional_table.getElementsByTagName('INPUT');
	

	for(i = 0; i < allElements.length ; i++)
	{
		if (allElements[i].disabled == true)
		{
			allElements[i].disabled = false;
		}
		else
		{
			allElements[i].disabled = true;
		}
		
	}
}