Unable to set attribute values in OnPostCreate

Hello

Is there any issue with below code as I wanted to update couple of attributes and its not working.

function onPostCreate($Request)
{

if ($Request.Class -ne "user") { return }
$samName = $Request.Get("sAMAccountName")
$fName = $Request.Get("givenName")
$lName = $Request.Get("sn")
$displayName = $Request.Get("cn").ToLower()
$result = $displayName -match $samName
WriteLog "$samName, $fname, $lName, $displayName, Result: $result"

if(!$result){
$name = $fName + " " + $lName + " (" + $samName+ ")"
WriteLog "Name: $name"
$DirObj.Put("displayName",$name)
$DirObj.Put("cn", $name)
$DirObj.SetInfo()
}
}

Thanks in Advance