Can someone explain me why this happens please?

Hi all, since I started playing around with Zend API, I thought it would be better to start writing some small functions as practice. Then my entire weekend became nightmare. I've tried to add a function activated in dynamic module, and it gives a very strange result. This function is really simple: taking an integer as argument, returns a 'hhhh:mm:ss' format string. If additional argument (BOOL) is set to true, then the 'hhhh' will turn to 'DD hh'. Now, it works fine while compiled with GCC alone in standard C style, but while working as a PHP function, the result is like this: (!靠备h2339:44:05 (!靠备窵▒97D 11:44:05 What are the characters in front of them? Where did they come? It's really confusing...... The original Zend style code is as follow: -------------------------------------------------------------------- ZEND_FUNCTION(cj_format_clock) { char res[50], myb[10]; long mys = 0; double myd, myh, mym; zend_bool useDay = 0; if ( zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS() TSRMLS_CC, "l|b", &mys, &useDay) == FAILURE ) { php_error(E_ERROR, "Expecting cj_format_clock([(INT)seconds])", get_active_function_name(TSRMLS_C)); return; } if ( mys < 0 ) { php_error(E_ERROR, "Number of second must be a possitive integer", get_active_function_name(TSRMLS_C)); return; } if ( useDay ) { myd = mys / 86400; mys %= 86400; sprintf(myb, "%.0f", myd); strcat(res, myb); strcat(res, "D "); } myh = mys / 3600; mys %= 3600; if ( myh < 10 ) strcat(res, "0"); sprintf(myb, "%.0f", myh); strcat(res, myb); strcat(res, ":"); mym = mys / 60; mys %= 60; if ( mym < 10 ) strcat(res, "0"); sprintf(myb, "%.0f", mym); strcat(res, myb); strcat(res, ":"); if ( mys < 10 ) strcat(res, "0"); sprintf(myb, "%d", mys); strcat(res, myb); RETURN_STRING(res, 1); }