Chrome extension autoupdate

I created an extension for chrome and I would like to up开发者_Go百科date themselves. However, I am unable to do so. Someone could tell me my mistake?

manifiest.json:

"update_url":"http://myhost.com/update.xml",
"version":"0.0.5.0"

update.xml:

<gupdate xmlns="http://www.google.com/update2/response" protocol="2.0">
<app appid="apoelbpnfhemjmnfkejmnfmdfhfhblii">
<updatecheck codebase="http://myhost.com/extension.crx" version="0.0.5.1"/>
</app>
</gupdate>

Sorry if I made mistakes, but I'm not native English.

Couple of suggestions...

I think update.xml should have <?xml version='1.0' encoding='UTF-8'?> at the top (if it doesn't already!)

In your sample code, the codebase value has myhost.com as the host -- is this correct in the 'real' update.xml?

The version above is different between manifest.json and update.xml -- is that deliberate here?