title: allow parentheses and other symbols in regex
body: <p>I've made this regex:</p>
  
  <pre><code>^[a-zA-Z0-9_.-]*$
  </code></pre>
  
  <p>Supports:</p>
  
  <pre><code>letters [uppercase and lowercase]
  numbers [from 0 to 9]
  underscores [_]
  dots [.]
  hyphens [-]
  </code></pre>
  
  <p>Now, I want to add these:</p>
  
  <pre><code>spaces [ ]
  comma [,]
  exclamation mark  [!]
  parenthesis [()]
  plus [+]
  equal [=]
  apostrophe [']
  double quotation mark ["]
  at [@]
  dollar [$]
  percent [%]
  asterisk [*]
  </code></pre>
  
  <p>For example, this code accept only some of the symbols above:</p>
  
  <pre><code>^[a-zA-Z0-9 _.,-!()+=“”„@"$#%*]*$
  </code></pre>
  
  <p>Returns:</p>
  
  <blockquote>
    <p>Warning: preg_match(): Compilation failed: range out of order in character class at offset 16</p>
  </blockquote>