Input string was not in a correct format. at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal) at System.Number.ParseInt64(String value, NumberStyles options, NumberFormatInfo numfmt) at System.Convert.ToInt64(String value) at NewsPublishingSystem.NewsArticle.Page_Load(Object sender, EventArgs e)