执行ajax成功的脚本

here is my javascript code in my php document:-

 ( function() {
if (window.CHITIKA === undefined) { window.CHITIKA = { 'units' : [] }; };
var unit = {"calltype":"async[2]","publisher":"soodsidhant","width":728,"height":90,"sid":"Chitika Default"};
var placement_id = window.CHITIKA.units.length;
window.CHITIKA.units.push(unit);
document.write('<div id="chitikaAdBlock-' + placement_id + '"></div>');
   }());

this javascript makes a div on loading just below where the script is placed.

and i have a separate x.js file which sends data through ajax... i want to execute the above code when get success.

one more thing if this script is executed from x.js where will it create the div in my site??? Also am i able to change that position???

i had already tried :- giving the script tag in my php document an id="ads" as [ answered here ] and calling it in ajax success by

eval(document.getElementById("ads").innerHTML);

and it didn't helped also with this method there was no error in console

Put this function in your file with the ajax request and then call it in the .succuess(...) callback from POST or PUT or whatever.