function grouping(data){
	var group = [];
	var i = 0;
	for(var k in date){
	   if(!data[k-1]){
	      group[i]=[];
	      group[i].push(data[k]);

	   }else{
	     if(data[k].username == data[k-1].username){
	       group[i].push(data[k]);
	     }else{
	       i++;
	       group[i]=[];
	       group[i].push(data[k]);
	     }
	   }
	}
  return group;
}