title: How to solve error: expected identifier or '('
body: <p>I've got a problem with something I'm programming.
  I get this error over and over;</p>
  
  <pre><code>jharvard@appliance (~/Dropbox/pset1): make mario
  clang -ggdb3 -O0 -std=c99 -Wall -Werror    mario.c  -lcs50 -lm -o mario
  mario.c:23:5: error: expected identifier or '('
      do
      ^
  mario.c:32:1: error: expected identifier or '('
  do
  ^
  2 errors generated.
  </code></pre>
  
  <p>I searched all over the internet but couldn't find the problem.. 
  removing the ; after <code>int main(void)</code> didn't help</p>
  
  <p>This is my code:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  #include &lt;cs50.h&gt;
  #include &lt;math.h&gt;
  
  int main(void);
  
      //Ask User for Height, and check
  
      int a, b, rows, height;
      int a = 0;
      int b = 0;
      int rows = 1;   
  
      do
      { 
          printf ("Height: ");
          height = GetInt();
      }
      while (height &lt;=0 || height &gt; 23);   
  
      //build half pyramid
  
      do
      {
          do
          {
              printf("r");
              a++;
          }
          while (a &lt; height - rows);
  
          do
          {
              printf("#");
              b++;
          }
          while (b &lt; rows + 1);
  
  
          printf("\n");
          rows++;
  
          while (rows &lt;= height);
      }
  </code></pre>
  
  <p>I've been trying to solve this problem for a few days, but i just can't figure it out!</p>
  
  <p>Thank you so much in advance!</p>