title: Show tooltip on textbox entry
body: <p>I have a <code>textbox</code> that requires data to be entered in a certain way. I have implemented some cell validating techniques to check the data after it has been entered, but I'd like to provide the user with some information before they enter the data.</p>
  
  <p>To that end, I'd like to add a <code>tooltip</code> to the <code>textbox</code> that pops up when the user enters the toolbox, then exits when they begin to type.</p>
  
  <p>For example I have the following code:</p>
  
  <pre><code>private void YearEdit_Enter(object sender, EventArgs e)
    {
          ToolTip tt = new ToolTip();
          tt.IsBalloon = true;
          tt.InitialDelay = 0;
          tt.ShowAlways = true;
          tt.SetToolTip(YearEdit, "Enter 4 digit year.");
      }
  </code></pre>
  
  <p>This executes when the user enters the <code>textbox</code>, however the <code>tooltip</code> only appears when the mouse hovers over the <code>textbox</code>. Does anyone have any ideas to work around this? I thought that perhaps <code>tt.ShowAlways = true</code> might work, but obviously not. </p>