model code

<?
class Admin extends AppModel {
var $name = "Admin";
var $validate = array(
'adminname' => VALID_NOT_EMPTY,
);

}
?>

controller coder

<?
class AdminsController extends AppController {
var $name = "Admins";


function add (){

}
function checkadd(){
if (!empty ($this ->data)) {
$fig = $this -> Admin ->save ($this -> data);
if ($fig) {
$this -> flash ("input admin sucess","/admins/listadmins");
} else {
$this -> flash ("input admin faild","/admins/add");
}
} else {
$this -> flash ("input admin info","/admins/add");
}
}

}
?>

view coder
<form method="post" enctype="multipart/form-data" name="theForm" id="form1" action ="<? echo $html->url("checkadd")?>">
<table width="100%">
<tbody>
<tr>
<td>Logname </td>
<td>
<? echo $html->input("Admin/adminname");?>
<? echo $html->tagErrorMsg("Admin/adminname","please input adminname");?>
* </td>
</tr>
<tr>
<td align="middle" colspan="2">
***<? echo $html->submit("Submit")?>
</td>
</tr>
</tbody>
</table>
</form>


i want to use cakephp validate

when submit the form .if empty of text (adminname) .will echo "please input adminname". on view thtml

when i submit it and the value of adminname empty .no message "please input adminname" echo . how can i do....