ERROR: System.InvalidCastException: Cast from string "" to type 'Double' is not valid. ---> System.FormatException: Input string was not in a correct format. at Microsoft.VisualBasic.CompilerServices.DoubleType.Parse(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.DoubleType.FromString(String Value, NumberFormatInfo NumberFormat) --- End of inner exception stack trace --- at Microsoft.VisualBasic.CompilerServices.DoubleType.FromString(String Value, NumberFormatInfo NumberFormat) at Microsoft.VisualBasic.CompilerServices.DoubleType.FromString(String Value) at ASP.Hangout_DataGrid_ascx.GetCollegeName()