ok you suggested me to terminate the lines with a ; and i did this:

Code:
function reset()
    {
    document.getElementById('TextBox1').value="";
    document.getElementById('TextBox2').value="";
    return false;
    }

  <asp:Button ID="Button2" runat="server" Text="Reset" OnClientClick="return reset()" />
still the button2 click causes the postback