infopath - Limit number of words in the text box -

i new info path, know how limit no.of characters entered in text box using string-length function. there way can limit number of words entered in multiline text box.

for example field asking enter 10 words lesser

found answer , wanted share it

set validation rule field(textbox). in condition select "the expression" , type below condition

string-length(field)-string-length(translate(field," ","")) <10 

here field name of textbox. , enter text in screen tip (eg: lesser 10 words) , click more option if want screentip , dialog box message. testing in preview type more 10 words , hit tab dialogue box lesser 10 words appear