Display a message or image when a request is in pr

Often, we want to notify the end user that an operation is in process; to let them know they may need to wait a bit for the operation to finish.  
First, let's define the message, what to do to show the message and what to do to hide the message:
   
and later (in the HTML of the page):
Loading, please wait a moment...
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With xajax 0.2.4 (the current release), you can accomplish this with the following javascript code:
   
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With xajax 0.5 (the current beta release), you can accomplish this with the following javascript code:
on a global level:
   
on a per call basis:
   
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With xajax 0.5, you have more flexibility.  Instead of a single loading message, you can now define a variety of loading messages.  In addition, you can use two or more loading messages simultaneously.
please see this post for a detailed description:
http://community.xajaxproject.org/viewt … 840#p13840