hello "anilr" , appreciate for your reply
"collect failed request tracing " —— actually , i don't know how to trace , but i knew a way by using a tool called "httpwatch" or firefox-firebug which could record all my request and response data , and also would be status-codes there.
and, sorry "anilr" , while i test again on a remote machine , it works again.
this make me find an interesting thing :
when i use http://localhost to test , it could not function correctly.
but if i use http://172.31.89.3 which is the ip of "localhost" , everything goes all right
could you explain that ?