title: ASP Classic: Check if string only consists of valid chars
body: <p>I've been checking all over the internet but really can't find any specific solution of my problem.</p>
  
  <p>How do I check if a string consists of only the declared valid characters?</p>
  
  <p>I want my string to consists of only 0-9, A-Z and a-z</p>
  
  <p>So the string <code>oifrmf9RWGEWRG3oi4m3ofm3mklwef-qæw</code> should be invalid because of <code>-</code> and <code>æ</code>
  while the string <code>joidsamfoiWRGWRGmoi34m3f</code> should be valid.</p>
  
  <p>I have been using the build-in RegExp to strip the strings, but is it possible to just make it check and return a boolean false or true?</p>
  
  <p>my regexp:</p>
  
  <pre><code>set pw = new regexp
  pw.global = true
  pw.pattern = "[^a-zA-Z0-9]"
  
  newstring = pw.replace("iownfiwefnoi3w4mtl3.-34ø'3", "")
  </code></pre>
  
  <p>Thanks :)</p>