private void button_click(object sender, EventArgs e)
{
if ((TResult.Text == "0") || (operationPerformed))
{
TResult.Clear();
dotCount = 0;
}
operationPerformed = false;
Button b = (Button)sender;
if (b.Text == "." && dotCount < 1)
{
dotCount++;
TResult.Text = TResult.Text + b.Text;
}
if (b.Text != ".")
{
TResult.Text = TResult.Text + b.Text;
}
}