Haidu,
Download the SDK at
http://developer.sonyericsson.com/site/global/docstools/java/p_java.jsp Install and go to the device explorer and use the on device debugging method (rightclick on the jad file).
It will install the MIDlet on the phone.
I have a k500i and the usb cable and it worked for me.
SCJP, SCMAD, SCWCD, SCBCD, CCIE (written), IBM 287<a href="http://hollandiahaven.blogspot.com/" target="_blank" rel="nofollow">.</a>