Error when complie compile_and_link sample

I test it on Ubuntu 11.10 with iDigi connector for Emb download from digi web and get errors, what should I do to preceed?

#make clean all

…omit useless output…

In file included from …/…/…/…/private/idigi_api.c:46:0:
…/…/…/…/private/idigi_fs.h:54:1: warning: padding struct size to alignment boundary [-Wpadded]
In file included from …/…/…/…/private/idigi_api.c:50:0:
…/…/…/…/private/idigi_fw.h:95:1: warning: padding struct size to alignment boundary [-Wpadded]
gcc -Wl,-Map,idigi.map,–sort-common debug.o main.o …/…/…/…/private/idigi_api.o -lc -lz -o idigi
/usr/bin/ld: cannot find -lz
collect2: ld returned 1 exit status
make: *** [idigi] Error 1

do "sudo apt-get install zlib1g-dev "