[jQuery] create new element in DOM

[joomlafreak]

I thought it is simple but why am I not able to achieve it, I don't
understand,

this is what I am doing

var isidThere = $("#tabcnt"+fileid_id);

        if (isidThere.size() != 1){

                $.get("files/"+fileid+".php",function(data){

                        
$("#tabcnt_"+rowopen).html(data).slideDown("slow",function(){
                        $("#tabcnt"+fileid_id).html(data);
//here I am trying to create a new element to store data for future
use without having to query it again form server

                        });
                        }else{

                        $("#tabcnt"+fileid_id).html(data);
                        $("#tabcnt_"+rowopen).html(data).fadeIn("slow");
                        }
                });
         }....

I thought this statement
$("#tabcnt"+fileid_id).html(data);

would create a new element in the DOM but even after going through the
loop the check on top throws isidThere.size() as 0, which means the
element is not there is DOM.

Can someone please guide me as to why the element is not being created
here to store the data.

many thanks in advance for any help.