vertion of opengl and 3d texture

when i use the glGetString(GL_VRTION),i get the number of “1.5.1” .Does it means that my opengl vertion is 1.5 ? And when i use the 3d texture like glTexImage3D() in my opengl it has wrong.What was the matter? 3D texture can be used in opengl 1.5 ,am i right?
thank you very much!

Read the FAQ yet?