ACCESS insert溢出问题

asp做 .net 链接access 总报溢出错误。请教。
string database = "E:\\YXY\\Solution1\\FirstPro.accdb";
            OleDbConnection con = new OleDbConnection(string.Format("ProVider=Microsoft.Ace.OLEDB.12.0;Data Source={0}", database));
           
            con.Open();
            OleDbCommand comd = con.CreateCommand();
            comd.CommandText = "insert into tablefirst([shangpin],[amount],[personname],[adress],[zipcode],[telephone],[payway],[time],[fuyan])values('" + spName.Trim() + "','" + txtamount.Text + "','" + txtperson.Text + "','" + txtadress.Text + "','" + txtzipcode.Text + "','" + txttelephone.Text + "','" + spPayway + "','" + spTime + "','" + txtfuyan.Text.Trim() + "')";
            object b = comd.ExecuteNonQuery(); 
           con.Close();
            int g = 0;
            g = int.Parse(b.ToString());
            if (g > 0)
            { Page.ClientScript.RegisterStartupScript(this.GetType(),"",  "<script language='javascript' defer>alert('添加成功');window.parent.location.herf='../Default.aspx';</script>"); }