Today I studied NextGEN gallery homepage. By following NextGEN gallery review introduction, I left all the setting by default. I upload all the previous post images. And then writing [ gallery=1 ] in the post, without space between square brackets will make the gallery with the id "1" shown in the post. From now on, I can't use add image button in ScribeFire for uploading images in my blog if I want to use this plugin. I will use it for now.