As Your Mother points out, this is much easier to implement on the client side. If you use jQuery your hidden field can be reduced to a boolean value and all you need do is something like: 
$("#id_of_textarea").change( function() {
  $("#id_of_textarea_changed").val(1);
});

[download]
I'm sure this would be easy enough in plain Javascript also.

In reply to Re: Compare Textarea Value to Hidden Field Value by tangent
in thread Compare Textarea Value to Hidden Field Value by phildeman

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