problems in extension development

hi, I just started to write a simple PHP extension "hello", but encountered some problems. I followed tutorials step by step: 1. ./ext_skel --extname=hello 2. modified hello.c and php_hello.h, and wrote function hello_world() which simply return a string "hello world". 3. phpize 4. ./configure ; make ; 5. the I encountered error in make. I looked up in Makefile and found that $(PHP_MODULE) is null, which I think is the reason. Makefile is automatically generated by ./configure. What mistake did I make? How to fix it? Thanks! Vic Hu -- Best regards, Rui Hu ---------------------------------------------------------------------------------------- State Key Laboratory of Networking & Switching Technology Beijing University of Posts and Telecommunications(BUPT) MSN: tchrbupt@gmail.com -----------------------------------------------------------------------------------------