Reflection Problem

Hi all: I have a problem when I am drawing the reflections. My code is like following:

void Reflection(){
    glDisable(GL_DEPTH_TEST);
    glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);
	
    glEnable(GL_STENCIL_TEST);
    glStencilOp(GL_REPLACE, GL_REPLACE, GL_REPLACE);
    glStencilFunc(GL_ALWAYS, 1, 0xffffffff);
	
    DrawCheckerBoard();

    glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);
    glEnable(GL_DEPTH_TEST);			
	
    glStencilFunc(GL_EQUAL, 1, 0xffffffff);  /* draw if ==1 */
    glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
    glPushMatrix();							
	glScalef(1.0f, -1.0f, 1.0f);
        DrawObject();
    glPopMatrix();
    glDisable(GL_STENCIL_TEST);	
}				

Outside this function I have enabled GL_BLEND and drawn the floor. The problem is that the object under the floor plane is always drawn as well. And I don't know how to remove it to just remain the reflection. I tried the method in NeHe's tutorial which uses glEnable(GL_CLIP_PLANE0); glClipPlane(GL_CLIP_PLANE0, eqr); glDisable(GL_CLIP_PLANE0); around the push and pop matrix. But it removed the reflection at the same time when I used it. Does anybody know where's the mistake please??? Thanks very much!!!