Event validation error and AJAX

[john_c]

Sometimes I get this error in an aspx page:

Invalid postback or callback argument. Event validation is enabled
using <pages enableEventVali dation="true"/in configuration or <%@
Page EnableEventVali dation="true" %in a page. For security purposes,
this feature verifies that arguments to postback or callback events
originate from the server control that originally rendered them. If
the data is valid and expected, use the
ClientScriptMan ager.RegisterFo rEventValidatio n method in order to
register the postback or callback data for validation.

The error occurs because I'm adding or removing controls/items via
AJAX. This gets out of synch with ASP.NET 2.0 and causes it to throw
the error. Setting EnableEventVali dation=false is supposed to make
the error go away.

I do have places where users can enter free text. If I want to use
AJAX this way, will I have to manually validate the entered in text.
Are there any scripts or techiniques to help with this?

Thanks,
John