ReportDocument serialization
I want to serialize a ReportDocument using XML serialization but in vain, that's my code: 

    public String serialiser (ReportDocument rd)
        {
            StringWriter sw= new StringWriter();
            System.Xml.Serialization.XmlSerializer xs = new System.Xml.Serialization.XmlSerializer(typeof(ReportDocument));
            xs.Serialize(sw, rd);
            return sw.ToString();
        }

NB: CrystalDecisions.CrystalReports.Engine.ReportDocument.

I got the following error:

    An error occurred during the reflection of the type 'CrystalDecisions.CrystalReports.Engine.ReportDocument'.

How could I serialize it?!
ReportDocument serialization
===

I want to serialize a ReportDocument using XML serialization but in vain, that's my code: 

    public String serialiser (ReportDocument rd)
        {
            StringWriter sw= new StringWriter();
            System.Xml.Serialization.XmlSerializer xs = new System.Xml.Serialization.XmlSerializer(typeof(ReportDocument));
            xs.Serialize(sw, rd);
            return sw.ToString();
        }

NB: CrystalDecisions.CrystalReports.Engine.ReportDocument.

I got the following error:

    An error occurred during the reflection of the type 'CrystalDecisions.CrystalReports.Engine.ReportDocument'.

How could I serialize it?!