my os win2000,cygwin... it puzzled me many days and i don't know how to solve it....anybody can help me?thanks,thanks,thansk a lot.... when i use my insight for M.Core....every time when i debug a simple example the program exit...just do like this i think you might get the problem... gcc-mcore -g file.c -o file.o and then open the file.o in insight using GUI mode.....set breakpoint at line 11,and the connect object target--sim,and run,then next.....the program exit,yes? the example: void my_print(char * string); void my_print2(char * string); #include main () { char my_string[] = "God save me!"; my_print (my_string); my_print2 (my_string); } void my_print (char *string) { /*line 11 the problem happens*/ printf ("The string is %s\n", string);} void my_print2 (char *string) { char *string2; int size, i; size = strlen (string); string2 = (char *) malloc (size + 1); for (i = 0; i < size; i++) string2[size - i] = string[i]; string2[size+1] = '\0'; printf ("The string printed backward is %s\n", string2); } how does this happen???thanks again....expect your reply.... _________________________________________________________________ ÏíÓÃÊÀ½çÉÏ×î´óµÄµç×ÓÓʼþϵͳ¡ª MSN Hotmail¡£ http://www.hotmail.com