范围问题（javascript）

I am running javascript variables from Mysql using PHP with Ajax/JSON. My original question can be found here: from mysql to javascript variable. Basically I now am having an issue with the variables being recognised throughout the remainder of the script. On my last question you see the two variables go from:

var tag_name = 'example';
var client_id = '123456789';

To now using (Thank you @Richard Rodriguez):

$.ajax({
   url: 'call.php',
   dataType: 'json'
}).done(
   function(data){
     var tag_name = data[0];
     var client_id = data[1];
   }
);

I believe the issue might just be a javascript function conflict? Here is a link to the script I am trying to modify from github: https://raw.github.com/ryancw/instagram-scroll/master/instagram-scroll.js. I hope seeing the original file can help diagnose what is causing the issue? I researched for that the last 2 hours with no luck. Any suggestions or even links to good articles on javascript function conflicts (if that is the issue) will be a great help.

EDIT (Full Code):

var tag_name = null;
var client_id = null;
var thumb_dimension = null;
var div_to_add_pics = null;
var include_caption = null;
var include_username = null;
var url = null;

function processData() {
   console.log(tag_name);
   console.log(thumb_dimension);  
    console.log(div_to_add_pics);
    console.log(include_caption);
   console.log(include_username);
   console.log(url);
}

$.ajax({
   url: 'call.php',
   dataType: 'json'
}).done(
   function(data){
     tag_name = data[0];
     client_id = data[1];
     thumb_dimension = 220;
    div_to_add_pics = '#img';
    include_caption = false;
    include_username = false;
    url = 'https://api.instagram.com/v1/tags/'+tag_name+'/media/recent?client_id='+client_id;
     processData();
   }
);

Your problem is scope not function conflict. The way the variables are declared they are visible in the local scope only, you either need to use them there, or pass them to another function that can use them, or (while polluting the global scope) declare them globally and remove the var keywords in the .done callback

using them locally

$.ajax({
   url: 'call.php',
   dataType: 'json'
}).done(
   function(data){
     var tag_name = data[0];
     var client_id = data[1];

     var clienttag = client_id+tag_name;
     //blah blah blah
   }
);

passing them to another function

function processData(tag_name,client_id) {
   console.log(tag_name);
   console.log(client_id);  
}

$.ajax({
   url: 'call.php',
   dataType: 'json'
}).done(
   function(data){
     var tag_name = data[0];
     var client_id = data[1];
     processData(tag_name,client_id);
   }
);

declaring globally (which is the least optimal as it pollutes the global space)

var tag_name = null;
var client_id = null;

function processData() {
   console.log(tag_name);
   console.log(client_id);  
}

$.ajax({
   url: 'call.php',
   dataType: 'json'
}).done(
   function(data){
     tag_name = data[0];
     client_id = data[1];
     processData();
   }
);