title: How to stop to reload page when click the button?
body: <p>I have asp.net website which include some calculation on button. When I press the button, my calculation works fine but, firstly page is refreshing and then the calculation looks on the label. I want to do that calculation looks on the label directly. Without refreshing. I give some codes.</p>
  
  <p>p.s. Also Page_Load has a function that receives daily exchange rates</p>
  
  <p><strong>ASP</strong></p>
  
  <pre><code>&lt;asp:Button ID="Button1" runat="server" BackColor="#990000" 
   BorderColor="#333333" ForeColor="White" onclick="Button1_Click" Text="Calculate" 
   Width="85px" BorderStyle="Outset" style="margin-left: 20px" 
   ValidationGroup="grup1" /&gt;
  </code></pre>
  
  <p><strong>BUTTON CLICK</strong></p>
  
  <pre><code>protected void Button1_Click(object sender, EventArgs e)
  {
  double sayi1, sayi2, sayi3, hesap, sonuc;
  
  sayi1 = Convert.ToDouble(Tb1.Text);
  sayi2 = Convert.ToDouble(Tb2.Text);
  sayi3 = Convert.ToDouble(Tb3.Text);
  
  
  if (Tb1.Text.Contains(".") || Tb2.Text.Contains(".") || Tb3.Text.Contains("."))
  {
    ...
    ...
    ...
  </code></pre>