function calcConc(form) {

    var concAmt = 0;

    for (var i = 1; i <= 3; i++) {

       var parsecheck = "" + parseFloat(form.elements[i].value);

       if (parseFloat(form.elements[i].value) < 0 ||

           parseFloat(form.elements[i].value) == 0 ||

           parsecheck == "NaN") {

          window.alert("Please enter a positive number in each of the " +

                       "three input fields.");

          return false;

       }

    }

    if (form.elements[5].checked == true) 

       concAmt = form.elements[1].value * form.elements[2].value *

                 (form.elements[3].value / 12.0) / 27;

    else 

       concAmt = form.elements[1].value * form.elements[2].value *

                 form.elements[3].value / 27;

    form.elements[7].value = formatvalue(concAmt,7);

    return true;

}

function calcCol(form) {

    var concAmt = 0;

    for (var i = 1; i <= 2; i++) {

       var parsecheck = "" + parseFloat(form.elements[i].value);

       if (parseFloat(form.elements[i].value) < 0 ||

           parseFloat(form.elements[i].value) == 0 ||

           parsecheck == "NaN") {

          window.alert("Please enter a positive number in both of the " +

                       "two input fields.");

          return false;

       }

    }

    var radius = form.elements[2].value / 24.0;

    concAmt = form.elements[1].value * radius * radius * Math.PI / 27;

    form.elements[4].value = formatvalue(concAmt,7);

    return true;

}

function calcWall(form)  {

    var concAmt = 0;

    for (var i = 1; i <= 2; i++) {

       var parsecheck = "" + parseFloat(form.elements[i].value);

       if (parseFloat(form.elements[i].value) < 0 ||

           parseFloat(form.elements[i].value) == 0 ||

           parsecheck == "NaN") {

          window.alert("Please enter a positive number in both of the " +

                       "two input fields.");

          return false;

       }

    }

    if (form.elements[3].checked == true)

       concAmt = form.elements[1].value * form.elements[2].value * 0.32 / 27.0;

    else

       concAmt = form.elements[1].value * form.elements[2].value * 0.51 / 27.0;

    form.elements[6].value = formatvalue(concAmt,7);

    return true;

}

function formatvalue(input, rsize) {

   var invalid = "**************************";

   var nines = "999999999999999999999999";

   var strin = "" + input;

   var fltin = parseFloat(strin);

   if (strin.indexOf("e") != -1 ||

       fltin > parseFloat(nines.substring(0,rsize)+".4"))

      return invalid.substring(0, rsize);

   if (strin.length <= rsize) return strin;

   var rounded = "" + (fltin + 

      (fltin - parseFloat(strin.substring(0, rsize))));

   return rounded.substring(0, rsize);

}

function clearform(form,count,lastElement) {

    for (var i = 1; i <= count; i++) form.elements[i].value = "";

    form.elements[lastElement].value = "";

}
function formtest(form){
	if ((form.D10.value == "" && form.D11.value == "") || (form.D20.value == "" && form.D21.value == "") || (form.D30.value == "" && form.D31.value == "")){
	alert("Certain dimensions are missing.");
	return false;
	}
	
	}
function formtest2(form){
	if ((form.DM.value == "" && form.DCM.value == "") || (form.LM.value == "" && form.LCM.value == "") ){
	alert("Certain dimensions are missing.");
	return false;
	}
	}