open aspx page in a new tab

dears, using a link button a new window is coming based on the pasted code below.how to open this same page in a new tab instead of a popup window using this same code structure in a link button? 
 

  Protected Sub LinkButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles LinkButton1.Click
         
Page.ClientScript.RegisterClientScriptBlock(Me.GetType(), "popup", "window.open('http://localhost:81/webform1.aspx?username=" & usd & "','','scrollbars=yes,menubar=no,height=700,width=600,resizable=yes,toolbar=no,location=no,status=yes')", True)
end sub
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