Blank window when i press select media link I have created a video content type, created a video field, and used media asset.
When I create a video node and click on "Select media," a blank popup shows up. In this blank popup, I have to choose in which way to upload file.

In the Firefox error console I see the following error:


  TypeError: this.contentWindow.Drupal.media is undefined


I am using Drupal 7.20 and the latest version of the Media module.
Use Firebug or Chrome Developer tools and look at the "Network traffic" and "Console" windows. I'll bet your getting a 404 or a JS related error in 1 of those windows.

You can then correct your server file permissions, fix the JS code error, or whatever.

You dont just have a blank page -- you have a blank page and an error reported somewhere.