I don't know why, but I use the command glFrustum to increase the far depth of the clipping plane, but I can't see more the object i created..
Here I post the relevant code.. I am now reading the red book, maybe I don't understand something..
please help me..it's very important..

Code :
	glMatrixMode(GL_PROJECTION);
	glLoadMatrixd( gl_para );
	glFrustum (-100.0, 100.0, -100.0, 100.0, 1.5, 2000.0);
	glMatrixMode(GL_PROJECTION);
 
        glRotated(180,1,0,0);
	glutWireCone(40,40*arrow_factor,10,100);
	glRotated(-180,1,0,0);