Why do I get a double entry in my database?

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ASP.NET

I get a double entry in my database when I signup a new user. I enter the user name and password that I made up and click submit. That part works but when i check the database I see the username twice. Why? What did I do wrong?

protected void Submit_Click(object sender, EventArgs e)
    {
        SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["HotConnectionString"].ConnectionString);
        con.Open();

        string cmdStr = "Select INST_ID, accessLevel, EmailAddress from Table1 where EmailAddress='" + TextBoxEA.Text + "'";
        string cmdStr2 = "Select INST_ID, accessLevel, EmailAddress from Table2 where EmailAddress='" + TextBoxEA.Text + "'";
        string insCmd = "Insert into Table22 (EmailAddress, Password, INST_ID, accessLevel) values (@EmailAddress, @Password, @INST_ID, @accessLevel)";
        string insCmd2 = "Insert into Table22 (EmailAddress, Password, INST_ID, accessLevel) values (@EmailAddress, @Password, @INST_ID, @accessLevel)";

        SqlCommand insertUser = new SqlCommand(insCmd, con);
        SqlCommand insertUser2 = new SqlCommand(insCmd2, con);

        insertUser.Parameters.AddWithValue("@EmailAddress", TextBoxEA.Text);
        insertUser.Parameters.AddWithValue("@Password", TextBoxPW.Text);
        insertUser.Parameters.AddWithValue("@INST_ID", TextBoxINST_ID.Text);
        insertUser.Parameters.AddWithValue("@accessLevel", TextBoxaccessLevel.Text);

        insertUser2.Parameters.AddWithValue("@EmailAddress", TextBoxEA.Text);
        insertUser2.Parameters.AddWithValue("@Password", TextBoxPW.Text);
        insertUser2.Parameters.AddWithValue("@INST_ID", TextBoxINST_ID.Text);
        insertUser2.Parameters.AddWithValue("@accessLevel", TextBoxaccessLevel.Text);

        try
        {
            insertUser.ExecuteScalar();
            insertUser2.ExecuteScalar();
            con.Close();
            Response.Redirect("Login.aspx");
        }
        catch (Exception er)
        {
            
        }
    }