How can I open image by clicking on post thumbnail?

[dunster]

Hi.

I try to make a post with only a featured image.
When I click on the thumbnail, it opens the post.
How can I open the original image by clicking on that thumbnail?

Thanks
dunster

[sayontan]

That cannot be done - clicking on the thumbnail will open the post.

[dunster]

And with a custom field?
That I can connect an external url to the title and thumbnail.

This plugin is something it does:
http://wordpress.org/extend/plugins/red ... tom-field/

Now to found out how I can add an target="_blank" or a class name to it so it will be open by Jquery popup.

When I add this at the end of the image link:
' target='_blank' class='thickbox no_icon'
it is working for the link in the post header, but not yet for the thumbnail link.

I can see that:
The header link works with single quotes and the thumbnail link works with double quotes.

Try to find out.
Any tips are welcome.