search dot('.') in string, why the sy-fdpos is zero?

Hi,

str = '136.59900'

search str for '.'

IF sy-subrc = 0.

pos = sy-fdpos.

ENDIF.

but pos is zero.

when i use 'CA' instead of search, result is str including dot. why? anybody give me an explanation?

if str ca '.'.

write:/ 'Including dot'.

else.

write:/ 'Not including dot'.

endif.