How to insert user and send email notification with password in apex trigge

The following trigger will insert a new user record when ever contact record is created and send email notification with password.

1. trigger PortalUserCreation on Contact (after insert) {
2.    
3.     List<User> userList=new List<User>();
4.    
5.     Profile pf = [SELECT Id FROM profile WHERE name='Standard User' limit 1];
6.    
7.     for(Contact objectContact:System.Trigger.new)
8.     {
9.         User mockUser=new User();
10.         mockUser.contactId=objectContact.Id;
11.         mockUser.username=objectContact.Email;
12.         mockUser.firstname=objectContact.FirstName;
13.         mockUser.lastname=objectContact.LastName;
14.         mockUser.email=objectContact.Email;
15.         mockUser.communityNickname = (objectContact.LastName +string.valueof(Math.random()).substring(4,9));
16.         mockUser.alias = string.valueof(objectContact.LastName.substring(0,1) +
17.                                         string.valueof(Math.random()).substring(4,9));            
18.         mockUser.profileid = pf.Id;
19.         mockUser.emailencodingkey='UTF-8';
20.         mockUser.languagelocalekey='en_US';
21.         mockUser.localesidkey='en_US';
22.         mockUser.timezonesidkey='America/Los_Angeles';
23.        
24.         // Mail alert Coding with temporary password
25.         Database.DMLOptions dlo = new Database.DMLOptions();
26.         dlo.EmailHeader.triggerUserEmail = true;
27.         dlo.EmailHeader.triggerAutoResponseEmail= true;
28.         mockUser.setOptions(dlo);  
29.         userList.add(mockUser);          
30.        
31.     }
32.     insert userList;
33.    
34. }