title: Using the function "IsNumeric" in vb.net
body: <p>I have a question about using the <code>IsNumeric()</code> function in VB.NET.
  <br>I have to make a program that says if the value in a TextBox is numeric or not.</p>
  
  <p>When I leave the <code>TextBox</code>, it has to display, in a <code>Label</code>, "your input is not numeric".
  <br>When I enter the <code>TextBox</code>, the text has to be deleted from the <code>TextBox</code>.</p>
  
  <p>I have no idea how to begin with this :/
  <br>Where do I have to place the code if I use a Windows Forms application and only have a closing button?</p>
  
  <p>I have tried about everything I know.</p>