install af php på suse linux personal 9.1

hvad går der galt her ?????????

linux:/home/jorn/php-4.3.10 # ./configure
--with-apxs2=/usr/local/apache2/bin/ap
xs --with-mysql
creating cache ./config.cache
checking host system type... i686-pc-linux-gnu
checking for gcc... gcc
checking whether the C compiler (gcc  ) works... yes
checking whether the C compiler (gcc  ) is a cross-compiler... no
checking whether we are using GNU C... yes
checking whether gcc accepts -g... yes
checking whether gcc and cc understand -c and -o together... yes
checking how to run the C preprocessor... gcc -E
checking for AIX... no
checking if compiler supports -R... no
checking if compiler supports -Wl,-rpath,... yes
checking for re2c... exit 0;
checking for ranlib... ranlib
checking whether ln -s works... yes
checking for mawk... no
checking for gawk... gawk
checking for bison... no
checking for byacc... no
configure: warning: You will need bison if you want to regenerate the PHP
parser                                            s.
checking for flex... lex
checking for yywrap in -ll... no
checking lex output file root... ./configure: line 2425: lex: command not
found
configure: error: cannot find output from lex; giving up
linux:/home/jorn/php-4.3.10 #