title: Match capital letters and small letters by RegExp
body: <p>I wrote some RegExp pattren like this :</p>
  
  <pre><code>SomeText
  </code></pre>
  
  <p>But I want the pattren to match with :</p>
  
  <pre><code>Sometext
  sOMeTeXt
  SOMETEXT
  SoMEteXt
  </code></pre>
  
  <p>Somethings like that !</p>
  
  <p>In fact I want to use this </p>
  
  <pre><code>\s?[^a-zA-Z0-9\_]SomeText[^a-zA-Z0-9\_]
  </code></pre>
  
  <p>what should i do ?</p>