Reference length of form fields in preventZoom function
Reference length of form fields in preventZoom function

This improves performance a little bit.

wjb12/mobile-boilerplate,cyprianos/bold,Cheeriohz/mobileWebPage,h5bp/mobile-boilerplate,filtercake/mobile-boilerplate-timetable-3,h5bp/mobile-boilerplate,Saajan/uber-mobile,fogbrain00/mobile-boilerplate,perfect-pixell/mobile-boilerplate,xieQin/mobile-boilerplate,xzcb2008/mobile-boilerplate,jamesandersen/jamesandersen.github.io,perfect-pixell/mobile-boilerplate,cyprianos/bold,Saajan/uber-mobile,xzcb2008/mobile-boilerplate,wjb12/mobile-boilerplate,filtercake/mobile-boilerplate-timetable-3,xieQin/mobile-boilerplate,jamesandersen/jamesandersen.github.io,COBSNAN/mobile-boilerplate,globalepub/mobile-boilerplate,COBSNAN/mobile-boilerplate,globalepub/mobile-boilerplate,texnixe/test