[thelist] window.self question

[michael grover]

Certain paid-for links on my site are getting hammered by spiders.  I 
have the idea that I can hide the links behind javascript and thwart the 
more stupid spiders.  But, I can't figure out how to use javascript in 
such a way that it won't go about opening a new window.

Here's what I start with:
<a href="#" onClick="window.open('target_page.html',''); return 
false;">Paid-for link</a>.

Now, I thought that I could change window.open to window.self and I'd be 
just fine.  But, it doesn't do it.

Any ideas?  Or, any other ideas for how I can obfuscate these links from 
  spiders while still making them usable by humans?

Thanks,

Mike.