title: Textbox validation to make sure has integer values only
body: <p><a href="https://i.stack.imgur.com/1sj5x.png" rel="nofollow noreferrer">Example textbox</a>
  Hi All, how can i add validate expression to only accept numeric and space in my textbox? Example as image above. I try this way ValidationExpression=&quot;[0-100' ']{100,}&quot; but not correct..</p>
  <pre><code>&lt;asp:TextBox ID=&quot;txtCopied&quot; runat=&quot;server&quot; TextMode=&quot;MultiLine&quot; 
  Height=&quot;200px&quot; Width=&quot;617px&quot; /&gt;
                                                         
  &lt;asp:RegularExpressionValidator ID=&quot;rvDigits&quot; runat=&quot;server&quot; 
  ControlToValidate=&quot;txtCopied&quot; ErrorMessage=&quot;Enter numbers only till 100 
  digit&quot; ValidationGroup=&quot;valGroup&quot; ForeColor=&quot;Red&quot; ValidationExpression=&quot; 
  [0-100' ']{100,}&quot;  /&gt;
  </code></pre>