Check interval of 4 seconds while inserting record in database using Stored Procedure in ASP.Net

I am taking input from user

Now i want to set interval of 3 second

means date if ETime is inserted =10:50:01, then next entry accept on Etime=10:50:04

    ALTER PROCEDURE [dbo].[spInsertPorderder] 
	-- Add the parameters for the stored procedure here
	@Codeitem int,
	@OrderNo int,
	@prdqty int,
	@IDWoker int,
	@EntryDate date,
	@FID int,
	--@PBsize varchar(50),
	@Weight int,
	@SecID int,
	@Rmk varchar (50),
	@ETime time(7),
	@BrefNo varchar (50),
	@IPAddress [varchar](50) ,
	@Gweigth int,
	@OID int output
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;


    IF NOT EXISTS 
    (
       SELECT ETIME, IPAddress,EntryDate  FROM Probale
       WHERE ETIME = @ETIME and IPAddress = @IPAddress and EntryDate=@EntryDate and Codeitem=@Codeitem
    )
    Begin 
	insert into Probale(Codeitem,OrderNo,prdqty,IDWokrer,EntryDate,FID,Weigth,SecID,Rmk,ETime,BrefNo,IPAddress,Gweigth ) 
	values(@Codeitem,@OrderNo,@prdqty,@IDWoker,@EntryDate,@FID,@Weight,@SecID,@Rmk,@ETime,@BrefNo,@IPAddress,@Gweigth )
	set @OID=SCOPE_IDENTITY()
    end
end

    SqlCommand cmd = new SqlCommand("spInsertPorderder", con);
    {
        // string mpid = Environment.UserName;
 
        if (txtpno.Text == "")
        {
            Response.Write("<script>alert('Please Select Order No')</script>");
 
        }
        else
        {                
            cmd.CommandType = CommandType.StoredProcedure;
            // cmd.Parameters.AddWithValue("@RollNo", TextBox4.Text.Trim());
            //  cmd.Parameters.AddWithValue("@Codeitem", ddpitem.SelectedValue);
            cmd.Parameters.AddWithValue("@Codeitem", txticode.Text.Trim());
            cmd.Parameters.AddWithValue("@OrderNo", txtpno.Text);
            cmd.Parameters.AddWithValue("@prdqty", prdqty.Text.Trim());
            cmd.Parameters.AddWithValue("@IDWoker", DDlWrknam.SelectedValue);
 
            cmd.Parameters.AddWithValue("@EntryDate", txtentrydate.Text);
            cmd.Parameters.AddWithValue("@FID", txtempid.Text);
            cmd.Parameters.AddWithValue("@PBsize", string.IsNullOrEmpty(txtpbs.Text) ? (object)DBNull.Value : txtpbs.Text);
            cmd.Parameters.AddWithValue("@SecID", DDSecbas.SelectedValue);
            cmd.Parameters.AddWithValue("@EmpiD", txtempid.Text);
            cmd.Parameters.AddWithValue("@ETime", DateTime.Now.ToString("HH:mm:ss"));
            cmd.Parameters.AddWithValue("@BaleSize", txtbs.Text);
 
            //    cmd.Parameters.AddWithValue("@CustomerID", hfdCustomerID.Value);
 
            cmd.Parameters.AddWithValue("@IPAddress", lblIP.Text);
            cmd.Parameters.Add("@OID", SqlDbType.Int);
            cmd.Parameters["@OID"].Direction = ParameterDirection.Output;
 
            con.Open();
            cmd.ExecuteNonQuery();
            int ResultValue = Convert.ToInt32(cmd.Parameters["@OID"].Value);
 
            if (ResultValue > 1)
            {
               //  Response.Redirect("SBPRView.aspx?OID=" + ResultValue + "");
                string Url = "SBPRView.aspx?oID=" + ResultValue;
                Response.Write("<script language='javascript'>window.open('" + Url + "','_blank','');");
                Response.Write("</script>");
            }
            else
            {
                Response.Write("<script>alert('Record Not save')</script>");
            }
            con.Close();
            txtpno.Text = "";
        }
    }