display message on dialog box

[tamhd_vn88]

I am learning about SugarCRM.i met some problem:
+ I want to dispay a message on a dialogbox ( exam display a message on a dialogbox when name='123')
+ I want to cancel save when a condition = true
+ I created 1 module to add new account.But i cant lgin by this account because password is wrong. In sugarCRM, use MD5, SHA or ....? and please show for me the way to use MD5 or SHA in file hook.
+ i want to take information of account login,after that display this infomation in a field.

Please help me!!!!

<?php

class kiemtra_class
{


function kiemtra_method(&$bean, $event, $arguments=null)
{
if ($event != 'before_save') return;
// Insert your custom logic between these comments
$query="select count(*) from md1_dangkykhachhang where name='$bean->name' and diachithuongtru='$bean->diachithuongtru' and dienthoaicodinh->'$bean->dienthoaicodinh'";
$results = $bean->db->query($query, true);
if ($bean->db->fetchByAssoc($results) == 0){
// Insert your custom logic between these comments

//show dialogbox
//cancel save in database


}

}

}

?>