Is this valid
Code :
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE2D, TextureID_01);
render
glBindTexture(GL_TEXTURE2D, TextureID_02);
render
glBindTexture(GL_TEXTURE2D, TextureID_03);
render
glBindTexture(GL_TEXTURE2D, 0);

Or do I have to unbind before I can bind a new texture?