Yeah!! I found my solution and lets share smile
Note: I put this at the first line of main( ) function.

What this code do? Change the resolution to the user native resolution IF, the screen wide up to 1680. If the user use bigger screen, change the resolution into their respective category. If the user use "strange" resolution, just make it window mode to be on the safe side.

The reason I limit the resolution for super big monitor is because they'll have huge advantage. Imagine you make a side scrolling game, of course wider screen will see the enemy sooner and have "more time" to avoid enemy attack.
Code:
desktopWidth = sys_metrics(0);
desktopHeight = sys_metrics(1);

if (desktopWidth<1681) video_set(desktopWidth,desktopHeight,0,1);
else
{
	if 	(desktopWidth/4  == desktopHeight/3)	//Classic
	{
		video_set(1024,768,0,1);
		desktopWidth = 1024;
		desktopHeight = 768;
	}
	else if (desktopWidth/15 == desktopHeight/9)	//BrightView
	{
		video_set(1280,768,0,1);
		desktopWidth = 1280;
		desktopHeight = 768;
	}
	else if (desktopWidth/5  == desktopHeight/4)	//SXGA
	{
		video_set(1280,1024,0,1);
		desktopWidth = 1280;
		desktopHeight = 1024;
	}
	else if (desktopWidth/16 == desktopHeight/10)	//WSXGA+
	{
		video_set(1680,1050,0,1);
		desktopWidth = 1680;
		desktopHeight = 1050;	
	}
	else						//Window Mode
	{
		video_mode = 8;
		video_window(nullvector,nullvector,1,NULL);
		wait(1);	// must put this. not sure the reason
		desktopWidth = screen_size.x;
		desktopHeight = screen_size.y;
	}
}

float fAspect = desktopWidth/desktopHeight;
camera.aspect = fAspect / 1.333333; // Not sure why have to hard code