commission rate display wrong when write commission textbox1

Question

my problem is cannot able to write any number in commission textbox (textbox1) and display result in textbox2 that represent commision rate .

 

commision rate = (commission/amount ) * 100

I have 3 text boxes

 

textbox1 : represent Commission

Commission=(amount * rate)/100

textbox2 : represent CommissionRate

CommissionRate=(Commission/amount)*100

 

txtLgAmount represent amount

private void textBox1_TextChanged(object sender, EventArgs e)
{

    if (!string.IsNullOrEmpty(textBox1.Text) && !string.IsNullOrEmpty(txtLgAmount.Text))
    {

       textBox2.Text = ((Convert.ToDecimal(textBox1.Text) / Convert.ToDecimal(txtLgAmount.Text))*100).ToString();

    }
    else
    {
        textBox2.Text = "";
    }
}

image problem attached below