In this case :
the HTML content(Note: the id contains a .):
<input id="register.address1" name="address1" class="text" value="" type="text">
the jQuery content:
$("#register.address1").css('display','none');
I am unable to make changes to this register.address1 because it contains a .. I concluded it after replacing the . with a - gave me desired result.
But as I am not allowed to change the register.address1 because the framework in which I am working does not allow me to do so. So what is other work around for this problem?