What is a good CSS style to represent "loading . . ."?

Question

I have been using blockUI which works great but I need to dynamically load a table row and from research it seems like blockUI doesn't work with HTML table rows.

I was just thinking of using:

jquery.AddClass("highlightCell") to start loading and jquery.RemoveClass() when the AJAX call returns.

Here is my current CSS but it doesn't look quite right so wanted to get some feedback or suggestions to show that a HTML table row is being "refreshed"

.highlightCell {
  background-color: #767070;
  -moz-opacity: 0.60;
  opacity: .60;
  filter: alpha(opacity=60);
}

Answer 1

I usually make one of this in an appropiate color and center them as background-image.