Help with widgets for ads

On some pages, Google shows ads. On some pages it doesn’t.

The space for the Google ads is a simple text widget with the Adsense code, placed in that part of the theme

I want to use Google as my main ads…. but how do I get other ad companies (that I have access to) to show on the pages in the spots Google wants to leave it blank because of inappropriate content

Thanks!

[please continue with http://wordpress.org/support/topic/help-with-theme-widgets-i-think?replies=1 ]