// Key to the Web, LTD. © 2000
function compute()
{
var width=document.fabric_calculator.block_width.value;
var height=document.fabric_calculator.block_height.value;
var across=document.fabric_calculator.blocks_across.value;
var down=document.fabric_calculator.blocks_down.value;
var fab_width=document.fabric_calculator.fabric_width.value;
var nwide=fab_width/width;
var number_wide= Math.floor(nwide);

var number_strips= Math.round((across * down)/number_wide);
var fabric_required = (number_strips * height) / 36;
document.fabric_calculator.total_yardage.value=format(fabric_required,1);
var lights=document.fabric_calculator.lights.value * .01 * fabric_required;
var mediums=document.fabric_calculator.mediums.value * .01 * fabric_required;
var darks=document.fabric_calculator.darks.value * .01 * fabric_required;
document.fabric_calculator.amount_light.value=format(lights,1);
document.fabric_calculator.amount_medium.value=format(mediums,1);
document.fabric_calculator.amount_dark.value=format(darks,1);
}

function reset()
{
document.fabric_calculator.block_width.value="";
document.fabric_calculator.block_height.value="";
document.fabric_calculator.blocks_across.value="";
document.fabric_calculator.blocks_down.value="";
document.fabric_calculator.fabric_width.value="";
document.fabric_calculator.total_yardage.value="";
document.fabric_calculator.amount_light.value="";
document.fabric_calculator.amount_medium.value="";
document.fabric_calculator.amount_dark.value="";
document.fabric_calculator.lights.value="";
document.fabric_calculator.mediums.value="";
document.fabric_calculator.darks.value="";

}

function format(expr,decplaces)
{
var str="" + Math.round (eval(expr) * Math.pow(10,decplaces));
while (str.length <= decplaces) 
	{
	str = "0" + str;
	}
var decpoint=str.length-decplaces;
return str.substring(0,decpoint) + "." + str.substring(decpoint,str.length);
}