function clear_values()
{
	document.getElementById('density').value = document.getElementById('density').options[0].value;
	document.getElementById('quantity').value = "";
	document.getElementById('thickness').value = "";
	document.getElementById('width').value = "";
	document.getElementById('length').value = "";

	document.getElementById('density_save').value = "";
	document.getElementById('quantity_save').value = "";
	document.getElementById('thickness_save').value = "";
	document.getElementById('width_save').value = "";
	document.getElementById('length_save').value = "";
	document.getElementById('total_save').value = "";
	document.getElementById('avg_per_sheet_save').value = "";

	document.getElementById('price_per_sheet_cell').innerHTML = '';
	document.getElementById('total_cost_cell').innerHTML = '';
	document.getElementById('request_quote_button_span').style.display = 'none';
	document.getElementById('place_order_button_span').style.display = 'none';
}

function round_number(float, dec)
{
	return Math.round(float * Math.pow(10, dec)) / Math.pow(10, dec);
}

function calculate()
{
	var quantity = document.getElementById('quantity').value;
	var thickness = document.getElementById('thickness').value;
	var width = document.getElementById('width').value;
	var length = document.getElementById('length').value;
	var density = document.getElementById('density').value;
	
	var error_msg = null;
	var error_fld = null;
	
	if (isNaN(length) || length > 999.99 || length < 0.1)
	{
		error_msg = "Please enter a value for the length.";
		error_fld = "length";
	}
	
	if (isNaN(width) || width > 999.99 || width < 0.1)
	{
		error_msg = "Please enter a value for the width.";
		error_fld = "width";
	}
	
	if (isNaN(thickness) || thickness > 999.99 || thickness < 0.1)
	{
		error_msg = "Please enter a value for the thickness.";
		error_fld = "thickness";
	}
	
	if (isNaN(quantity))
	{
		error_msg = "Please enter a correct quantity.";
		error_fld = "quantity";
	}

	if (error_msg)
	{
		document.getElementById(error_fld).focus();
		document.getElementById(error_fld).select();
		alert(error_msg);
		return;
	}
	
	var deviation = 0.125;
	var value = 0.0026077859148725290457573922140851;
	var density_value = 0.0;
	
	switch (density)
	{
		case '1.0':
			density_value = 0.13;
			break;
			
		case '1.5':
			density_value = 0.16;
			break;
		
		default:
			density_value = 0.20;
	}

	var lwt = length * width * thickness;
	var step1 = lwt / 144;
	var step2 = step1 * 3.9875; /* was 3.625 on 7/15/08 */
	var per_sheet = step2 * density_value;
	var total = per_sheet * quantity;
	var avg_per_sheet = round_number(per_sheet, 2);
	var total = round_number(total, 2);
	total = (total < 250.00) ? 250.00 : total;
	
	document.getElementById('quantity_save').value = quantity;
	document.getElementById('thickness_save').value = thickness;
	document.getElementById('width_save').value = width;
	document.getElementById('length_save').value = length;
	document.getElementById('density_save').value = density;
	document.getElementById('total_save').value = total;
	document.getElementById('avg_per_sheet_save').value = avg_per_sheet;

	document.getElementById('price_per_sheet_cell').innerHTML = '$' + avg_per_sheet;
	document.getElementById('total_cost_cell').innerHTML = '$' + total;
	document.getElementById('request_quote_button_span').style.display = 'block';
	document.getElementById('place_order_button_span').style.display = 'block';
}

function submit_specs(type)
{
	var quantity = document.getElementById('quantity').value;
	var thickness = document.getElementById('thickness').value;
	var width = document.getElementById('width').value;
	var length = document.getElementById('length').value;
	var density = document.getElementById('density').value;
	
	var quantity_save = document.getElementById('quantity_save').value;
	var thickness_save = document.getElementById('thickness_save').value;
	var width_save = document.getElementById('width_save').value;
	var length_save = document.getElementById('length_save').value;
	var density_save = document.getElementById('density_save').value;
	var total_save = document.getElementById('total_save').value;
	var avg_per_sheet_save = document.getElementById('avg_per_sheet_save').value;
	
	if (density != density_save || quantity != quantity_save || width != width_save || length != length_save || thickness != thickness_save)
	{
		alert('At least one value has changed since your last calculation.  Recalculating now...');
		calculate();
		return;
	}
	
	/*
     	var url = '/how-to-order?source=eps_pricing&type=' + type + '&density=' + density +
		'&quantity=' + quantity + '&thickness=' + thickness + '&width=' + width + '&length=' + length +
		'&avg_per_sheet=' + avg_per_sheet_save + '&total=' + total_save;
	
	*/		
		var url = '/how-to-order?specs=Type: ' + type + ' / Density: ' + density + 'lb Thickness= ' + thickness + '  Width= ' + width + ' Length= ' + length + ' / EPS Pricing Info / Quantity: ' + quantity + ' / Cost Per Sheet= $' + avg_per_sheet_save + ' / TOTAL COST= $' + total_save
	window.location = url;
}