vc++6.0中写的OpenGL 函数 一个小问题，请大家帮帮忙。
//#include<iostream.h>
#include<windows.h>
#include<gl/gl.h>
#include<gl/glu.h>
#include<gl/glaux.h>

void CALLBACK RenderScene(void)
{
glClearColor(1.0f, 1.0f, 0.0f ,0.0f);
glClear(GL_COLOR_BUFFER_BIT);
glColor3f(1.0f, 0.0f, 0.0f);

glMatrixMode(GL_MODELVIEW);
glLoadIdentity( );

auxSolidSphere(0.5f);

glFlush( );
_sleep(4000);
}

void main(void)
{
auxInitDisplayMode(AUX_SINGLE | AUX_RGBA);
auxInitPosition(0.0f ,0.0f, 1000.0f, 1000.0f);
auxInitWindow("simply");

//Set function when windows needs updating
auxMainLoop(RenderScene);
//return 0;
}
没有错误和警告，但是，我所期望在创建的窗口中显示所画的球不能实现。

[解决办法]
glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
...
glFlush( );
auxSwapBuffers(); // 交换绘图缓存
_sleep(4000);