Knockout js getting page(s) unresponsive error while using continuously

Question

I'm using KnockOut js in Chat functionality. In the left panel, Users will be displayed and on clicking the user, Chat conversation will be displayed in the Right Panel. Now, My Problem is after few clicks, the browser is getting over loaded and popping out the page unresponsive error.

Is there anything like Clear Cache(Garbage Collection) kind of thing for browser?

I've tried aborting the old request, if any new request was made by using this code.

 if (xhr != null) {
            xhr.abort();
            xhr = null;
        } 

Is there anything I can do with Threading in Javascript?