title: Block Specific Words with Regular Expressions
body: <p>I'm still learning about Regular expressions, still little bit confused using it.</p>
  
  <p>My case :
  I need block some specific word in input html with javascript or jquery.</p>
  
  <p>Words i need to block is admin or administrator keyword, i don't want people using keyword like admin or administrator when create new account (username).</p>
  
  <p>I need to block keywords like admin, 4dmin, adm1n, 4dm1n or even ADMIN, 4Dm1N..No matter user input in lowercase or uppercase or even numeric to replace letter "A" with numeric "4".</p>
  
  <p>For now my code is :</p>
  
  <pre><code>var input = document.getElementById("inputUser");
  input.onkeyup = function() {
      input.value = input.value = input.value.replace(/(admin|4dmin|adm1n|4dm1n)/,"");
  }
  </code></pre>
  
  <p>Please help dear masters, i'm stuck at this moment, any help i very appreciate.</p>