textbox autopostback textchanged cause multiple postback on chrome

The problem is I am showing a popup on TextChanged event and it shows the popup after the event but then another postback happens which hides the popup
<asp:TextBox runat="server" ID="txtTestAutoPostBack" AutoPostBack="true" OnTextChanged="TextChanged"></asp:TextBox> after you typed something and then hit enter two postbacks will occur.
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