Submit a form while the validation has fired problem

<asp:Button ID="ButtonSubmit" runat="server" CausesValidation="True" onclick="ButtonSubmit_Click" 
                    Text="Submit" Width="75px" />

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

        SqlCommand cmd = new SqlCommand("Insert into Table2013 (INST_ID, FT_UNDERGR, DATE, FT_GRAD, FTE_UNDERG, FTE_GRAD, NON_CREDIT, TOTAL_FTE, FCFTUHC, FCFTPBHC, FCPTUHC, FCPTPBHC, NCHC, FTEYR, TIME) values (@INST_ID, @FT_UNDERGR, @DATE, @FT_GRAD, @FTE_UNDERG, @FTE_GRAD, @NON_CREDIT, @TOTAL_FTE, @FCFTUHC, @FCFTPBHC, @FCPTUHC, @FCPTPBHC, @NCHC, @FTEYR, @TIME)Insert into Table2014 (INST_ID, FT_UNDERGR, DATE, FT_GRAD, FTE_UNDERG, FTE_GRAD, NON_CREDIT, TOTAL_FTE, FCFTUHC, FCFTPBHC, FCPTUHC, FCPTPBHC, NCHC, FTEYR, TIME) values (@INST_ID, @FT_UNDERGR, @DATE, @FT_GRAD, @FTE_UNDERG, @FTE_GRAD, @NON_CREDIT, @TOTAL_FTE, @FCFTUHC, @FCFTPBHC, @FCPTUHC, @FCPTPBHC, @NCHC, @FTEYR, @TIME)", con);

        cmd.CommandType = CommandType.Text;
        cmd.Parameters.AddWithValue("@INST_ID", TextBoxINST_ID.Text);
        cmd.Parameters.AddWithValue("@FT_UNDERGR", TextBoxFTUG.Text);
        cmd.Parameters.AddWithValue("@FT_GRAD", TextBoxFTG.Text);
        cmd.Parameters.AddWithValue("@FTE_UNDERG", TextBoxTHUGDR.Text);
        cmd.Parameters.AddWithValue("@FTE_GRAD", TextBoxTHGDR.Text);
        cmd.Parameters.AddWithValue("@NON_CREDIT", TextBoxNCCDR.Text);
        cmd.Parameters.AddWithValue("@TOTAL_FTE", TextBoxTCNC.Text);
        cmd.Parameters.AddWithValue("@FCFTUHC", TextBoxTNFUG.Text);
        cmd.Parameters.AddWithValue("@FCFTPBHC", TextBoxTNFG.Text)
        cmd.Parameters.AddWithValue("@FCPTUHC", TextBoxTNCPUG.Text);
        cmd.Parameters.AddWithValue("@FCPTPBHC", TextBoxTNCPG.Text);
        cmd.Parameters.AddWithValue("@NCHC", TextBoxTNNCC.Text);
        cmd.Parameters.AddWithValue("@FTEYR", lblYEAR.Text);
        cmd.Parameters.AddWithValue("@DATE", TextBoxDATE.Text);
        cmd.Parameters.AddWithValue("@TIME", lblTime.Text);

        cmd.ExecuteNonQuery();
        con.Close();

        if (Page.IsValid)
        {
            ScriptManager.RegisterStartupScript(this, this.GetType(), "script", "alert('You Have Successfully Submitted the Enrollment Profile');", true);
        }
        else
        {
            Response.Redirect("Gradrate.aspx");
        }