creating a drupal non-cached template variable

In drupal 6 开发者_StackOverflowI'm trying to execute a function on every page and output a different link based on what IP address someone is coming from. However, when I try this, it seems that the result is getting cached. I have tried this as a module and in template.php, but have not gotten results. What is the best approach to make sure this function executes on every page load? Or is there an easy way to create a template variable that does not get cached?

Is it possible for you to use a block instead with BLOCK_NO_CACHE or BLOCK_CACHE_PER_USER as the block caching policy? If you put a block like this in a region above/below you could achieve a very similar effect on any page you like, node or otherwise.