Issue with using $(document) with .html()

Issue with using $(document) with .html()

I am loading some HTML with some .js files to a DIV using .html().. If I load in the the same more than once, than my JS functions get fired off that many times..ex:  

$(document).on('click', '.folderOpen', function(){
    alert(this.id);
});

If I load the div 3 times, then I see that alert 3 times.. its like the head isn't clearing the .js files when the div gets repopulated.  I tried .html('') and .empty() before it gets reloaded.  Any suggestions?