title: What I need to declare in this scope?
body: <p>I'm doing this little program  in C++ but in codeblocks appears the following error: error: </p>
  
  <blockquote>
    <p>'atod' was not declared in this scope</p>
  </blockquote>
  
  <p>What I'm missing in this code? Thank you.</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;conio.h&gt;
  #include &lt;string.h&gt;
  #include &lt;fstream&gt;
  #include &lt;math.h&gt;
  #include &lt;iostream&gt;
  
  using namespace std;
  
  
  class birth{
  };
  
  
  int main (void){
  
      int pass=1;
      string date, boy, aux1, aux2, aux4;
      double f;
  
      while(pass=! 0){
          cout&lt;&lt;"Enter the name of the birthday boy"&lt;&lt;endl;
          cin&gt;&gt;boy;
          cout&lt;&lt;"Enter the date of birth" &lt;&lt;endl;
          cin&gt;&gt;date;
          aux1= aux1.substr(5,10);
          f= atod(aux1);
          f=2012-f;
          cout&lt;&lt; "The birthday boy "&lt;&lt;boy&lt;&lt;"who born"&lt;&lt;date&lt;&lt;"now have"&lt;&lt;f&lt;&lt;"years"&lt;&lt;endl
  
  
          cout&lt;&lt;"Do you want to enter more birthdays?"&lt;&lt;endl;
          cout&lt;&lt;"1.- YES"&lt;&lt;endl;
          cout&lt;&lt;"2.- NO"&lt;&lt;endl;
          cin&gt;&gt;pass;
      }
  
      system ("pause");
      return 0;
  };
  </code></pre>
  
  <p>EDIT: The problem is in this line:</p>
  
  <pre><code> f= atod(aux1);
  </code></pre>