当我点击这个文本框时它会变大但当我点击时我怎么让它恢复正常？

i'm basically mimicking the share button feature on facebook with jquery and what im trying to do is when i click on the textbox area the textbox gets larger by height. and when i click away it should get back to normal. with the last piece of jquery the code doesnt work at all. what are my options in getting this to work? thanks.i'm basically mimicking the share button featur