st: Create dummy

[mmolina@uniroma3.it]

Dear Statlist,
I need to create a dummy from a double variable (sí, no, no sabe)
I wrote:
gen quality = 0
replace quality = 1 if b8=="no"

And I received the message

type mismatch
r(109);

What should I do?

Thanks and regards,
Alejandra Molina



*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/