function program1()
{
	h1 = eval(document.sp_enclosure.h1.value);
	w1 = eval(document.sp_enclosure.w1.value);
	d1 = eval(document.sp_enclosure.d1.value);
	
	thickness = eval(document.sp_enclosure.thickness.value);
	box_volume = (document.sp_enclosure.box_volume.value);
	document.sp_enclosure.thickness.value = eval(document.sp_enclosure.thickness.value);
	if (document.sp_enclosure.thickness.value >= 0)  h1 = (h1-(thickness*2));
	if (document.sp_enclosure.thickness.value >= 0)  w1 = (w1-(thickness*2));
	if (document.sp_enclosure.thickness.value >= 0)  d1 = (d1-(thickness*2));
	
	document.sp_enclosure.box_volume.value = ((h1*w1*d1)/1000);
	document.sp_enclosure.box_volume.value = (document.sp_enclosure.box_volume.value*1000);
	document.sp_enclosure.box_volume.value = Math.round(document.sp_enclosure.box_volume.value);
	document.sp_enclosure.box_volume.value = (document.sp_enclosure.box_volume.value/1000);
}