Validate
------------------------------------------------------------------------
Use the ErrorProvider control with the FlexGrid.

The ErrorProvider control allows you to display a blinking caret next 
to any data-entry control, with a tooltip that describes the error.

It is often a better option that popping up a MessageBox, or showing
a string in a status bar where it might go unseen.

The sample checks the data in the grid's ValidateEdit event. If the
data is invalid, it sets the ErrorProvider text associated with the
grid, which causes the blinking error icon to appear.