convert crystal report to pdf and send as email

Dear All,

Im doing an application in which i have created a crystal report from database. I was able to send the report as attachment in email. But the extension is rpt. How can i convert the report to pdf and send the pdf as attachment. I have tried so many ways but everything is failing. here is my code.

using system.web.mail;

private bool SendWebMail(string strTo, string subj, string cont, string cc, string bcc, string strfrom)
{

// generating crystal reports


DataTable dre = bus.generatereport();
rd.Load(Server.MapPath(Request.ApplicationPath) + "/user/MonthlyReport.rpt");
rd.SetDataSource(dre);


bool flg = false;
MailMessage msg = new MailMessage();
msg.Body = cont;
msg.From = strfrom;
msg.To = strTo;
msg.Subject = subj;
msg.Cc = cc;
msg.Bcc = bcc;
msg.Attachments.Add(new MailAttachment(Server.MapPath(Request.ApplicationPath) + "/user/MonthlyReport.rpt"));
msg.BodyFormat = MailFormat.Html;
try
{
//SmtpMail.SmtpServer = "175.143.44.165";
SmtpMail.SmtpServer = "192.168.1.4"; // change the ip address to this when hosting in server
SmtpMail.Send(msg);
flg = true;
}
catch (Exception)
{
flg = false;
}
return flg;
}

How can i send pdf instead of rpt.

Thanks in advance,

Agaile