Respones.Redirect Problem ???

protected void btnaddparty_Click(object sender, EventArgs e)
    {
Response.Redirect("taxinvoice_print.aspx");//I want this page open in new tab(like Target="_blank")
Response.Redirect("taxinvoice.aspx");
   }

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show i want that txtinvoice_print.aspx open in new tab ,and txtinvoice.aspx open in current tab

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