Multiple Graph Output

//OpenGL functions, open a window and initialize
void display(void)
{
	glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT);
	glLoadIdentity();
	//issue the GL commands
	glTranslatef(-.3, 0., 0.);
	glRotated(45.,0., 1.,0.);
	glScalef(.5, .5, .5);
	glColor3f(0., 0., 0.);
	glBegin(GL_LINES);
	I = 0.;
	do
	{
		//draw the axes
	if (I==0)
		{
		glVertex3f(0., 0., 0.);
		glVertex3f(1., 0., 0.);
		glVertex3f(0., 0., 0.);
		glVertex3f(0., 1., 0.);
		glVertex3f(0., 0., 0.);
		glVertex3f(0., 0., 1.);
		glVertex3f(0., 0., 0.);
		}
	//draw the curve
		glVertex3f(PLOTX[I], PLOTY[I], PLOTZ[I]);
		glVertex3f(PLOTX[I + 1], PLOTY[I + 1], PLOTZ[I + 1]);
		++I;
	} while (I <= INOW);
	glEnd();
	glFlush();

Have the above sequence of commands in the "visual" function, using the OpenGL glutInit and execute commands. Strange that the only output that I get is for the coordinate axes, not the curve data in the "do" loop? INOW=45

Sid Kraft