function myConvert() {
    var FromVal, ToVal, FromName, ToName, v1;

    v1 = document.MainForm.what.value;
    v1 = stripBad(v1);
    v1 = parseFloat(v1);
    if (isNaN(v1)) v1 = 0;
    document.MainForm.what.value = v1;

    FromVal = document.MainForm.from[document.MainForm.from.selectedIndex].value;
    ToVal = document.MainForm.to[document.MainForm.to.selectedIndex].value;
    FromName = document.MainForm.from.options[document.MainForm.from.selectedIndex].text;
    ToName = document.MainForm.to.options[document.MainForm.to.selectedIndex].text;

    var ConvertedTemp = get_fact(v1, FromVal, ToVal);
    if (ConvertedTemp == "Below Absolute Zero") {
        document.MainForm.answer.value = "Your input cannot be below absolute zero.";
    } else {
    //        document.MainForm.answer.value = v1 + " " + FromName + " = " + ConvertedTemp + " " + ToName;
    document.MainForm.answer.value = ConvertedTemp;
    }
}

function resetAnswer() {
    document.MainForm.answer.value = "";
}

function get_fact(ff, from_val, to_val) {
    // first convert to kelvin
    if (from_val == 0) {
        ff = ff + 273.15;
    } else if (from_val == 1) {
        ff = ((ff - 32) / 1.8) + 273.15;
    } else if (from_val == 2) {
        ff = ff / 1.8;
    } else if (from_val == 3) {
        ff = (ff * 1.25) + 273.15;
    }

    if (ff < 0) {
        // Below absolute zero
        return "Below Absolute Zero";
    }

    // now convert kelvin to unit
    if (to_val == 0) {
        ff = ff - 273.15;
    } else if (to_val == 1) {
        ff = (1.8 * (ff - 273.15)) + 32;
    } else if (to_val == 2) {
        ff = ff * 1.8;
    } else if (to_val == 3) {
        ff = (ff - 273.15) / 1.25;
    }

    // round it off
    if (Number.prototype.toFixed) {
        ff = ff.toFixed(7);
        ff = parseFloat(ff);
    }
    else {
        var leftSide = Math.floor(ff);
        var rightSide = ff - leftSide;
        ff = leftSide + Math.round(rightSide * 10000000) / 10000000;
    }

    return ff;
}

function stripBad(string) {
    for (var i = 0, output = '', valid = "eE-0123456789."; i < string.length; i++)
        if (valid.indexOf(string.charAt(i)) != -1)
        output += string.charAt(i)
    return output;
}