The code looks fine to me (except you don't need the ; at the end of the last line). Check your error log; perhaps the browser thinks capturePhoto is not defined for some reason. You can also add alert statements to make sure the code is actually running:
var photo = "yes";
alert('Entering if statement');
if (photo=="yes") {
alert('then');
capturePhoto();
} else {
alert('else');
//do nothing
}
When you encounter a situation where it seems like a fundamental language feature is not working, get some more information about what is going on. It is almost never the platform's fault. It is occasionally a misunderstanding of how the feature works (e.g. why does parseInt('031') == 25 ?). It is usually a violation of an assumption you're making about the code that isn't holding up because of a problem elsewhere.
capturePhoto()do? Unless your JS/browser install is totally hosed, or either of thoseyesstrings are ninjas pretending to be yesses, there's no way that this code could NOT call capturePhoto.true/falseboolean constants rather than"yes"/"no"strings. You could then format yourifasif (photo) capturePhoto();.