Stencil buffer problem ?

Hello .
I have a big problem .
I can not work with stencil buffer .
When I draw a object , OpenGL display it in frame buffer either I call before it “glStencilFun(GL_NEVER,…” or “glStencilFun(GL_ALWAYS,…” .
What is my mistake ?
Thankyou before your favour.

did you initialize the buffer, clear it end enable stenciling