I need help regarding sending mail thru Outlook.

On Click of a button I need to open a new outlook message
with to,subject and body pre-typed.

I used a code similar to this(used MS Outlook library) and I get errors:

Outlook.Application oa=new Outlook.Application();
Outlook.MailItem om= Outlook.MailItem();
om=oa.CreateItem(om);
om.To ="sdasaf";
om.Subject="dfgdg";
om.Body="dfgdfg";

Help me out.