function toggle_category_list(item_id)
{
	if (document.getElementById('category_expand'+item_id).style.display != 'block')
	{
		document.getElementById('category_expand'+item_id).style.display = 'block';
		document.getElementById('category_expand_title'+item_id).style.backgroundColor = '#FFFFFF';
		document.getElementById('category_expand_title'+item_id).style.border = '0px';
		document.getElementById('category_expand_image'+item_id).src = 'images/category_main/minus-sign.gif';
	}
	else
	{
		document.getElementById('category_expand'+item_id).style.display = 'none';
		document.getElementById('category_expand_title'+item_id).style.backgroundColor = '#FFFFFF';
		document.getElementById('category_expand_title'+item_id).style.border = 'none';
		document.getElementById('category_expand_image'+item_id).src = 'images/category_main/plus-sign.gif';
	}
}

function show_compare_tip(product_id)
{
	set_compare_tip_text();
	document.getElementById('compare_tip_div').style.visibility = 'visible';
	
	document.getElementById('compare_tip_div').style.top = (get_position_y(document.getElementById('div_compare_'+product_id)) - 20 - document.getElementById('compare_tip_div').offsetHeight) + 'px';
	document.getElementById('compare_tip_div').style.left = (get_position_x(document.getElementById('div_compare_'+product_id)) + 10) + 'px';
}

function hide_compare_tip()
{
	document.getElementById('compare_tip_div').style.visibility = 'hidden';
}

function submit_comparison_form(f)
{
	if (get_number_of_products_selected_for_comparison() < 2)
	{
		alert('Please select at least two products before clicking the "Compare" link');
		return false;
	}
	
	f.submit();
}

function set_compare_tip_text()
{

	products_selected_for_comparison=get_number_of_products_selected_for_comparison();
	
	if (products_selected_for_comparison < 1)
	{
		document.getElementById('compare_tip_div').innerHTML = 'Check the boxes next to the products you want to compare and then click the "compare" link';
	}
	else if (products_selected_for_comparison == 1)
	{
		document.getElementById('compare_tip_div').innerHTML = 'Please select at least one more product and click the compare link when you\'re ready';
	}
	else
	{
		document.getElementById('compare_tip_div').innerHTML = 'You can click the compare link when you\'re ready ('+products_selected_for_comparison+' products currently checked, maximum of 10)';
	}
}
function get_number_of_products_selected_for_comparison()
{
	products_selected_for_comparison=0;
	myform = document.getElementById('product_comparison_form');
	for (var i=0; i< myform.elements.length; i++)
	{
		if (myform.elements[i].type == 'checkbox')
		{
			if (myform.elements[i].checked)
			{
				products_selected_for_comparison++;
			}
		}
	}
	
	return products_selected_for_comparison;	
}

function get_position_y( input_element )
{
	position = 0;
	
	while (input_element != null)
	{
		position += input_element.offsetTop;
		input_element = input_element.offsetParent;
	}
	
	return position;
}

function get_position_x( input_element )
{
	position = 0;
	
	while (input_element != null)
	{
		position += input_element.offsetLeft;
		input_element = input_element.offsetParent;
	}
	
	return position;
}

function toggle_criteria(caller, element_to_update)
{
	if (document.getElementById(element_to_update).style.display == 'block')
	{
		document.getElementById(element_to_update).style.display = 'none';
		caller.innerHTML = '+ More';
	}
	else
	{
		document.getElementById(element_to_update).style.display = 'block';
		caller.innerHTML = '- Less';
	}
}

function show_change_zip_form(caller)
{
	document.getElementById('change_zip_table').style.visibility = 'visible';
	document.getElementById('change_zip_table').style.top = (get_position_y(caller) + 20 - document.getElementById('change_zip_table').offsetHeight*0) + 'px';
	document.getElementById('change_zip_table').style.left = (get_position_x(caller) + caller.offsetWidth - document.getElementById('change_zip_table').offsetWidth ) + 'px';
}

function hide_change_zip_form()
{
	document.getElementById('change_zip_table').style.visibility = 'hidden';
}