**fig4_23.txt**

/* 1*/	template <class Etype>
/* 2*/	void
/* 3*/	Binary_Search_Tree<Etype>::
/* 4*/	Insert( const Etype & X, Tree_Node<Etype> * & T )
/* 5*/	{
/* 6*/	    if( T == NULL )
/* 7*/	    {
/* 8*/	        T = new Tree_Node<Etype>( X );
/* 9*/	        if( T == NULL )
/*10*/	            Error( "Out of space" );
/*11*/	    }
/*12*/	    else
/*13*/	    if( X < T->Element )
/*14*/	        Insert( X, T->Left );
/*15*/	    else
/*16*/	    if( X > T->Element )
/*17*/	        Insert( X, T->Right );
/*18*/	    // Else X is in the tree already.  We'll do nothing.
/*19*/	}