title: how to code the itemchanged event and datawindows
body: <p>I am using PowerBuilder classic 12.5
  am having difficulties in inserting, editing, creating and printing reports.</p>
  
  <p>i have a datawindow, <code>dw_NewEmployee</code> with dataobject, <code>d_newrecord</code> which is update-able.</p>
  
  <ol>
  <li>should i use the columns to insert records through the columns or i 
  create single line texts on the window object</li>
  <li>is the <code>itemchanged</code> event used on columns and rows on dataobject or 
  on single line texts... I am having trouble figuring out how to implement validation rules.
  please give me an example to validate employee <code>ID_Number</code></li>
  </ol>