The Weird and The Wonderful

function checkMonth(oMonth) {
                if (parseInt(oMonth.value) != NaN) {
                    if (parseInt(oMonth.value) > 12) {
                        oMonth.value = parseInt(oMonth.value) - 12;
                    }
                }
                else {
                    oMonth.value = "";
                }
            }

function checkDay(oDay) {
    if (parseInt(oDay.value) != NaN) {
        if (parseInt(oDay.value) > 31) {
            oDay.value = parseInt(oDay.value) - 31;
        }
    }
    else {
        oDay.value = "";
    }
}

/// <summary>
/// Works around a bug in the form designer.  Doesn't do any painting logic.
/// </summary>
/// <param name="sender">Unused.</param>
/// <param name="e">Unused.</param>
/// <remarks>
/// Is putting this line here to stop columns from auto-generating in the designer a WTF?
/// Yes, but so is this being the only way to do it if you want anything other than 100% default
/// datbound columns without having to do all the grid layout without the aid of the designer.
/// The AutoGenerateColumns property can't be set in the designer and the constructor is already too late.
/// </remarks>
private void DataGridView1Paint(object sender, PaintEventArgs e)
{
     dataGridView1.AutoGenerateColumns = false;
}

=(1-(K11-L11)/K11)*100