title: visual studio c++ error link1120
body: <p>I was writing a C++ program in visual studio 2013 and the
  program is very simple one and when I compile there was error
  this is third time I see this error.
  Here's the program:</p>
  
  <pre><code>#include &lt;iostream&gt;
  using namespace std;
  
  int main()
  {
      int x, y, z = 0;
      char c;
      bool quit = true;
  
      while (quit == true)
      {
          cout &lt;&lt; "enter a number : ";
          cin &gt;&gt; x;
          cout &lt;&lt; "enter a sign : ";
          cin &gt;&gt; c;
          cout &lt;&lt; "enter another number : ";
          cin &gt;&gt; y;
  
          if (c == '+')
              z = x + y;
          if (c == '-')
              z = x - y;
          if (c == '*')
              z = x * y;
          if (c == '/' &amp;&amp; y != 0)
              z = x / y;
          if (c == 'q')
              quit = false;
  
          cout &lt;&lt; "Answer is : " &lt;&lt; z &lt;&lt; endl;
      }
  
      return 0;
  }
  </code></pre>
  
  <p>...and here's the error:</p>
  
  <pre><code>1&gt;------ Build started: Project: Calculator_madeByMe, Configuration: Debug Win32 ------
  1&gt;  Source.cpp
  1&gt;MSVCRTD.lib(crtexew.obj) : error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup
  1&gt;C:\Users\Sorena\documents\visual studio 2013\Projects\Calculator_madeByMe\Debug\Calculator_madeByMe.exe : fatal error LNK1120: 1 unresolved externals
  ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========&gt;
  </code></pre>