UNIX for Dummies Questions & Answers

Hey all, im trying to create a makefile in unix. cpp2html is a program created from the files cpp2html.o and lex.yy.o.
cpp2html.o is created from compiling cpp2html.c and lex.yy.o is created from another created file lex.yy.c. and lex.yy.c is created from a command "flex cppscanner.l" and here is what i have so far

Code:

cpp2html: cpp2html.o lex.yy.o 
	gcc -g -DDEBUG cpp2html.o lex.yy.o
	mv a.out cpp2html
 
cpp2html.o: cpp2html.c
	gcc -g -DDEBUG -c cpps2html.c
 
lex.yy.o: lex.yy.c
	gcc -g -DDEBUG -c lex.yy.c

i do not know where to implement the command "flex cppscanner.l" to make the file lex.yy.c any suggestions would be great

add:

Code:

lex.yy.c: cppscanner.l
        flex cppscanner.l

right before the lex.yy.c line.
Make sure that the word "flex" is proceeded by a TAB only.