The TinyMCE can't select local image?

I install my Gallery2 and bridge it with Drupal successfully.

But after I install Wysiwyg and TinyMCE, I can edit my blog entry in full text editor mode.

But while I select to upload my local image, I think I can't select my local PC's image. There is just one blank for me to input the URL of image.

so, how?