g++ cannot find header file
<p>I am migrating from Java to C++. It seems that C++ makes classes declaration in separate files, difficult. So I need your help,</p>

<p>in my main.cpp:</p>

<pre><code>#include "Sphere.h"

using namespace std;
.....
...
..

int main( void ) {
   Sphere *earth = new Sphere(sphere_start ,sphere_end);
...
..
.
</code></pre>

<p>in my Sphere.h</p>

<pre><code>class Sphere
{

    public:
        Sphere(int,int);

}
</code></pre>

<p>and in my Sphere.cpp</p>

<pre><code>#include "Sphere.h"

using namespace std;

int sphere_start, sphere_end;   

Sphere::Sphere (int a, int b)
{
    sphere_start = a;
    sphere_end = b;
}

void Sphere::render(int i) 
{
   ....
   ..
   .

}
</code></pre>

<p>This is the very basic code that I think causes the following error:</p>

<pre><code>main.cpp:14:20: fatal error: Sphere.h: No such file or directory
compilation terminated.
</code></pre>

<p>why?</p>
