Support for a Null STBoxIndex

PROMS/VEPROMS.CSLA.Library/Format/vlnFormat.cs

@@ -408,6 +408,7 @@ namespace VEPROMS.CSLA.Library
 				int iValue = 0;
 				if (!int.TryParse(xn.InnerText, out iValue))
 				{
+					if (xn.InnerText == "") return null;
 					Console.WriteLine(string.Format("'{0}'\r\n'{1}'\r\n'{2}' could not be converted to int?", MyFormat.FullName, MyPath + "/" + xPath, xn.InnerText));
 					throw (new Exception(string.Format("{0} = '{1}' could not be converted to int?", xPath, xn.InnerText)));
 				}