Now, when I am accessing them for fetching their values, I need to check whether they are initialized or not. If they are not initialized the access to variable will return NULL. But I am not sure how to do that. I am a bit confused, when I tried this
if (!var_name) alert("var_name not assigned");
I got an error
ERROR : var_name is not defined.
I had already declared the variable var_name, although i had not assigned it. How to get this work ?