I am successfully posting a form via ajax, using the following code;

 $.post( "Page.do?source=ajax", 
            $("#Form").serialize(), 
            function(data){ 


                }

The data response that comes back can be alert'd. I can see that it is the HTML of the entire form, having been submitted. But, I am having trouble accessing an element in that form which has come via ajax, ie

data.find('.Errors').html() 

or

$('.Errors', data).html()

Do I need to somehow convert the text into a DOM which can then be parsed by jQuery?