CMS Script Runtime Error

Input string was not in a correct format.

Exception Details: System.FormatException

Exception Source: mscorlib

Stack Trace:

   at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
   at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
   at Zynex.CMS.CustomCode.ArtikelDetailHandlerBase.OnLoad()
   at Zynex.CMS.CustomCode.ArtikelDetailHandler.OnLoad()
   at Zynex.CMS.CustomCode.WebRequest.OnLoad()
   at Zynex.CMS.Web.HttpHandler.PageProcessor.ProcessRequest(RequestParam rp)