media uploader showing half on screen

im creating a word press plugin and i want my users to be able to upload the image via the wordpress uploader or use an image in their media already.

when i call the loader my thick box(iframe) shows half on screen and half off screen.
i followed this Tut
https://www.webmaster-source.com/2010/01/08/using-the-wordpress-uploader-in-your-plugin-or-theme/

as i said only the right half of the box shows the other half is off the screen