why applet can't write data into servlet by url

now my applet can get data from servlet ,but can't send data to servlet .I test this program in the tomcan and local computer .thanks for ur help!
[168 byte] By [concentrate] at [2007-9-26 6:40:29]
# 1

I would imagine that your attempt to write to the servlet is violating some applet security restriction. Remember that applets can not write to the local file system, nor can they contact any server other then the base server where they were downloaded from. Look at the security restrictions a little more closely- perhaps you need to use a signed applet or run the servlet engine remotely.

rvflannery at 2007-7-1 15:58:37 > top of Java-index,Core,Core APIs...