Ok, I still need help.  What is happening now is that if the user doesn't attach an attachment, I get an error.  Please help is you can....I am stuck.

Thanks,

Quanchi

Below is my current code in my Apex Class:

public class sendEmail {
   public String subject { get; set; }
   public String note { get; set; }
   public String fileName1 { get; set; }
   public blob filebody1 { get; set; }
               
          
   private final Opportunity Opportunity;

    // Create a constructor that populates the opportunity object
   
    public sendEmail() {
        opportunity = [Select statement goes here from opportunity where id = :ApexPages.currentPage().getParameters().get('id')];
    }

    public opportunity getopportunity() {
        return opportunity;
    }

    public PageReference send() {
   
        // Define the email
         
        Messaging.SingleEmailMessage email = new Messaging.SingleEmailMessage();

        String[] toAddresses = new String[] {'email@address.com'};
        String[] bccAddresses = new String[] {'email2@address.com'};
        String[] ccAddresses = new String[] {'email3@address.com};
       
        email.setReplyTo('email4@address.com');
        email.setSenderDisplayName('Salesforce');
        email.setUseSignature(false);
        
        // Sets the paramaters of the email
   
        email.setSubject( 'New RFP - '+ Opportunity.Name + ' - '+ Opportunity.Owner_Name__c);
        email.setToAddresses( toAddresses );
        email.setCcAddresses( ccAddresses );
        email.setbccAddresses( bccAddresses );
       
        //   Attachments
                
          Messaging.EmailFileAttachment efa = new Messaging.EmailFileAttachment();
          efa.filename = null;
          efa.body = null;
          efa.setFileName(fileName1);
          efa.setBody (fileBody1);
                
        email.setFileAttachments(new Messaging.EmailFileAttachment[] {efa});

            
        email.setHtmlBody('email body goes here');
    
     // Sends the email

      Messaging.SendEmailResult [] r =
           Messaging.sendEmail(new Messaging.SingleEmailMessage[] {email}); 

    // redirects user to a thank you page after the email is sent.  
      { 
        PageReference p = Page.ThankYou; 
        p.setRedirect(true); 
        return p; 
      }

                        
    }

}