function perRound(num, precision) {
	var precision = 3; //default value if not passed from caller, change if desired
	precision = parseInt(precision); // make certain the decimal precision is an integer
    var result1 = num * Math.pow(10, precision);
    var result2 = Math.round(result1);
    var result3 = result2 / Math.pow(10, precision);
    return zerosPad(result3, precision);
}



function zerosPad(rndVal, decPlaces) {
    var valStrg = rndVal.toString(); // Convert the number to a string
    var decLoc = valStrg.indexOf("."); // Locate the decimal point
    // check for a decimal
    if (decLoc == -1) {
        decPartLen = 0; // If no decimal, then all decimal places will be padded with 0s
        // If decPlaces is greater than zero, add a decimal point
        valStrg += decPlaces > 0 ? "." : "";
    }
    else {
        decPartLen = valStrg.length - decLoc - 1;
        // If there is a decimal already, only the needed decimal places will be padded with 0s
    }
     var totalPad = decPlaces - decPartLen;    // Calculate the number of decimal places that need to be padded with 0s
    if (totalPad > 0) {
        // Pad the string with 0s
        for (var cntrVal = 1; cntrVal <= totalPad; cntrVal++)
            valStrg += "0";
        }
    return valStrg;
}

// send the value in as "num" in a variable
// clears field of default value

function clear_field(field) {
		if (field.value==field.defaultValue) {
			field.value=''
		}
	}

function convertdb2watts(form)
{
  form.expr.value = eval(form.expr.value);
  form.result.value = dbw2watts(form.expr.value);
}

function convertwatts2db(form)
{
  form.expr.value = eval(form.expr.value);
  form.result.value = watts2dbw(form.expr.value);
}

function dbw2watts(inValue)
{
  return Math.round(Math.pow(10,eval(inValue)/10)*100000)/100000;
}

function watts2dbw(inValue)
{
  return Math.round(10 * Math.log(eval(inValue))/Math.LN10 * 100000)/100000;
}