The best way is to use AJAX ( you can find a simple tutorial on this page Tizag). The reason is that any other technique you may use requires more code, it is not guaranteed to work cross browser without rework and requires you use more client memory by opening hidden pages inside frames passing urls parsing their data and closing them. AJAX is the way to go in this situation. That my two years of javascript heavy development speaking.

The best way is to use AJAX (you can find a simple tutorial on this page Tizag). The reason is that any other technique you may use requires more code, it is not guaranteed to work cross browser without rework and requires you to use more client memory by opening hidden pages inside frames passing urls parsing their data and closing them. AJAX is the way to go in this situation. That is my two years of javascript heavy development speaking.