Page with TabContainer problem

Hi,
i have problem regarding Tabcontainer.i have a tabcontainer with three tab in my form.there are 8 control in each tab.when i click on submit button for insert data to database,then a message box is display and that time my tabcontainer is vanish and after click Ok button of Messagebox again Tabcontainer is display.
i use following syntax for display message box.
  ClientScript.RegisterStartupScript(GetType(Page), "alert", "<script language=JavaScript>alert('" & Record Inserted Sucessfully! & "');</script>")
i also try like below
ScriptManager.RegisterOnSubmitStatement(Me, GetType(Page), "alert", "alert('Record Inserted Sucessfully!');")
please help me, what is the error and why it is so?
Thanking you.
      

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