title: How To Only Allow Alpha Numeric Chars With JavaScript
body: <p>Been playing around with JavaScript, and what Im trying to do is only allow certain characters in the pass word field - a-z, A-Z and 0-9.</p>
  
  <pre><code>&lt;form action="http://www.cknuckles.com/cgi/echo.cgi" method="get" name="logOn"&gt;
    User Name:&lt;br /&gt;
    &lt;input type="text" name="userName" size="25" /&gt;&lt;br /&gt;
    Password:&lt;br /&gt;
    &lt;input type="password" name="pw" size="25" /&gt;&lt;br /&gt;
    &lt;input type="submit" value="Log In" onClick="validate()"/&gt; 
  &lt;/form&gt;
  </code></pre>
  
  <p>Above is my HTML, and Below is my JavaScript I tried to use to validate it - but it doesnt work - any clues.</p>
  
  <pre><code>&lt;script language="javascript"&gt;
     document.logOn.onsubmit=validate;
  
     function validate(){
  
  var name=document.logOn.pw.value;
      if(!name = "[a-zA-Z0-9]"){              
  alert("Your Password Cant Have Any Funky Things In It - Play It Straight!");
      return false;
  }               
  
      return true;
  }
  &lt;/script&gt;
  </code></pre>
  
  <p>But This isnt working. I can still put chars in like "*" and "[" and "{" etc.</p>
  
  <p>Any Thoughts?</p>