Effective way to notify user of input validation failures in an editable table

Im looking for ideas on how to effectively notify users that their input into an editable table is invalid. For example, if one column of a table represents an American zip code and the user enters in the zip code "85rr3" into a cell, how would you notify the user of the issue?

From stackoverflow

• I'd probably highlight it in red after entered, then maybe a warning at the top of the table.

• I think it's effective enough to just delete the value if it's not a valid zip code.

  Tobias Schulte : Just deleting the value might not be very nice to the user for other types of fields, for example for Street names, because the user does not want to re-enter everything just because he did one typo in one char.

• Highlighting the field while typing is one nice way to do it or you can go the MS Access route and wait until moving out of the cell, notify the user, and bring them back into the cell until it's fixed (or give the option to hit Esc or something to undo all changes in that cell and leave 'edit mode')

• In .net WinForms you can use the Error Provider control

  

  Attach the error message to the control when its invalid

  errorProvider1.SetError (textBox1,"Error Message");

  and clear the message when its valid

  errorProvider1.SetError (textBox1,"");

  You can position the location of the icon using the Icon Alignment and padding fields

  • errorProvider1.SetIconAlignment (textBox1, ErrorIconAlignment.MiddleRight);
  • errorProvider1.SetIconPadding (textBox1, 2);