Fetech contacts data in excel sheet through visual force page

<apex:page controller="FetchdatathroughCSV" sidebar="false" action="{!Fetechdata}" cache="false" contentType="text/plain/#contacts.csv">
<apex:repeat value="{!con}" var="r">
  {!r.firstname}{!r.lastname}
</apex:repeat>

</apex:page>

public class FetchdatathroughCSV
{
 public List<Contact> con {get;set;}
 public PageReference Fetechdata()
 {
   con = [Select Id ,firstName ,LastName from contact limit 10];
   return null;
 }

}