What I need to declare in this scope?
<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>
