replacing or managing json data from ajax request

Answer 1

Everything declared with the var keyword inside of your function(data) will be created anew each time the function is called.

What's the symptom of your problem? Have you actually looked at the value of the uids variable in firebug and seen that items are being duplicated, or do you just see your dates/names getting doubled up on the page?

My suspicion is that this is a result of not clearing the DOM elements that you are calling .append() on before you display your results.

Try adding to the beginning of the function:

$('div#holdDates').empty();

as well as to your date display loop:

$('ul#'+date).empty();

and for good measure, at the beginning of function:

$('li.show').unbind('click');