title: Required a number in text box in Inno Setup
body: <p>I found a code here that I needed. To only allow write numbers in a text box. But I still wanted more, which does not offer up the "Next" button without write the number in this text box. </p>
  
  <p>Can help me?</p>
  
  <pre class="lang-pascal prettyprint-override"><code>procedure NumbersOnly(Sender: TObject; var Key: Char);
  var
    S: string;
  begin
    S := ('1234567890'#8);
    if Pos(Key, S) = 0 then 
      Key := #0;
  end;
  </code></pre>