Load page and run javascript

Question

I have an existing script (in a bookmarklet) that only works with the http:// version of the page. When I am on the https:// version of the page, I want to load the http:// version using:

add = window.location.href;
if(add.indexOf('https') == 0){
  window.location.href = 'http' + add.slice(5);
}

and then allow the bookmarklet to run on the new page. Is there a way to do this ?

Right now, I added the code above to the bookmarklet, and click it twice: the first click loads the http:// version of the page and the second click runs the original bookmarklet.

Thanks !!