JQuery :: JSON - Refreshing Request Second Time After Page Loads

I'm using some jQuery to work with the Last.FM API, and I'm stuck where I need to allow the user to run the JSON request a second time after the page loads (it loads once automatically when the page loads, the second time is when they push a button). What happens currently, is the JSON function is fed some default data when the page loads:

$('#graph').lastFM({
username: 'UserName',
from: 1254369600,
to: 1256184000,
apikey: 'myApiKeyHere',
onComplete: function(){
//Done
}});

The JSON function:
$.fn.lastFM = function(options) {
var defaults = {
username: 'Verdani',
apikey: 'e4f3bb251d13179bf7ce80a089fb3d0c',
onComplete: function(){}
},
settings = $.extend({}, defaults, options); .....

You might have noticed in the JSON, I write the URL the JSON is requesting to the console every time it runs. When I click this button, a new URL pops up in the console below the first one but only for a second, and then the page reloads and the original JSON request is called. It's this loop that I can't seem to break out of - why does re-calling the JSON refresh the page?