<!-- Begin
function quantvol() {
len = document.RectCal.len.value;
wid = document.RectCal.wid.value;
thi = document.RectCal.thi.value;
document.RectCal.RecResult.value=Math.round((len*wid*(thi/100))*10000)/10000
textmessage = ' ';
if (thi <= 6){textmessage = 'Use fine grade gravel/ballast for this thickness of concrete.';}
if (thi <= 3){textmessage = 'This thickness is a bit on the thin side for concrete to have any strength. ';}
document.RectCal.Message.value = textmessage;
}

function circlevol() {
rad = document.CircleCal.rad.value;
thi = document.CircleCal.thick.value;
document.CircleCal.CirResult.value=Math.round(((3.14*rad*rad)*(thi/100))*10000)/10000
textmessage = ' ';
if (thi <= 6){textmessage = 'Use fine grade gravel/ballast for this thickness of concrete.';}
if (thi <= 3){textmessage = 'This thickness is a bit on the thin side for concrete to have any strength. ';}
document.CircleCal.CirMessage.value = textmessage;
}

function trivol() {
base = document.TriCal.TriBase.value;
height = document.TriCal.TriHeight.value;
thi = document.TriCal.TriThi.value;
document.TriCal.TriResult.value=Math.round(((base/2)*height*(thi/100))*10000)/10000
textmessage = ' ';
if (thi <= 6){textmessage = 'Use fine grade gravel/ballast for this thickness of concrete.';}
if (thi <= 3){textmessage = 'This thickness is a bit on the thin side for concrete to have any strength. ';}
document.TriCal.TriMessage.value = textmessage;
}
//  End -->