Edit in JSFiddle

function getPagedTweets(pageNumber){
  var cnt=100;
  var url = "http://search.twitter.com/search.json?&page=" + pageNumber + "&rpp=" + cnt + "&q=india&lang=en&include_entities=true&result_type=mixed&callback=?";
   $.getJSON(url, function(response){
       for(var i=0;i<response.results.length; i++){  
          if (response.results[i].entities.urls[0]) 
                    {
                      expandedURL = "[ <i><a href='" + response.results[i].entities.urls[0].expanded_url + "' >" + response.results[i].entities.urls[0].expanded_url + "</a></i> ]";
                    }
                    else
                    {
                        expandedURL = "";
                    }
         $('#tweets').append("<li>" + response.results[i].text + " " + expandedURL + "</li>");
    }});
  };
  
  function nextPage(){
  var pageNumber = parseInt($('#tweets').attr("data-nextpage"));
  getPagedTweets(pageNumber);
  $('#tweets').attr("data-nextpage", pageNumber + 1);
};

$(document).ready(function(){
  getPagedTweets(1);
  $(window).scroll(function(){
    if($(window).scrollTop() >= $(document).height() - $(window).height()){
      console.log( "scrollTop: " + $(window).scrollTop() +  " - $(document).height(): " + $(document).height() + " - $(window).height(): " + $(window).height() )
      nextPage();
    };
  });
});

<ul id='tweets' data-nextpage="2"></ul>