// in h1.h file
struct H1 : public WithTest2Layout<TopWindow> {
public:
	typedef H1 CLASSNAME;
	H1();
	void AddNum(int a, int b){
		if(a>=b) 
			t1<<="1 OK";	
	}

        void AddNum2(int a, int b);
	void Set_t1(String a) {t1<<=a;}
};


// in h2.h file

#include "h1.h"

// it is now valid to call Set_t1 as AddNum2 is now also in the 
// same class scope.

void H1::AddNum2(int a, int b){
	if ( a > b )
//		t1<<="2 OK";
		Set_t1("2 OK");	

}

class H1{
    public:
           int t1; // t1 is in the class h1's scope
           // this function also in h1's scope
           void AddFun1(int a, int b)
           { 
              t1=a+b; // valid t1 access.
           
            }
    
};

// regardless weather the below function is in
// h1.h or h2.h or main.cpp or anyother file in
// that matter is still in global scope

void AddFun2(int a, int b) 
{
   // this is function scope
  // t1 is not visible here
  // no object of H1 class also is non existent
  // since you did not create any.

  // but you can do this:

  H1 c;
  c.AddFun1(1,1);
  cout<<c.t1;
  
  c.t1=a+b;
  cout<<c.t1;

  // all t1 of c object of H1 class are valid but c gets 
  // destroyed as soon as function scope is finish.


}

//H1 c;
void Try2(){
//		t1<<="2 OK";
//		c.Set_t1("H2 OK");
		;	
}

H2.h
#include "H1.h"
void H1::Try2(){
    Set_t1("H2 OK");
}
but in H1.h
//#include "H2.h" // this must be commented out