var classes = {};
$('.jspane *[id]').each(function(){
if(classes[this.id])
return $(this).remove();
classes[this.id] = true;
});
*[id]
, а .chat[id]
. var abc = "ABCDEFGH";
for(var i = 0; i < abc.length; i++){
var button = document.createElement("button");
button.textContent = abc[i];
container.appendChild(button);
}