function set_present(div_id, class_name)
{
	if(document.getElementById(div_id) != undefined)
	    document.getElementById(div_id).className = class_name;
}

function get_present(div_id)
{
	if(document.getElementById(div_id) != undefined)
		return document.getElementById(div_id).className;
}

function hide_present(div_id)
{
	if(document.getElementById(div_id) != undefined)
	    document.getElementById(div_id).style.display = 'none';
}

   function set_off(option_id)
{
	set_present(option_id, '');
}

function show_option(div_id) {
    hide_present('item_description');
	hide_present('specifications');
	hide_present('enquire');


	set_off('item-description-option');
	set_off('specifications-option');
	set_off('enquire-option');


    document.getElementById(div_id).style.display = 'block';
	document.getElementById(div_id + '-option').className = 'on';
}