function Tank(form)
{form.volume.value = (Math.round(form.length4.value * form.width4.value * form.height4.value /1000))}

function Tankinch(form)
{form.volume1.value = (Math.round((form.length4.value*2.54) * (form.width4.value*2.54) * (form.height4.value *2.54)/1000))}