Dispose Data Table In Asp.net And .net?

I Want to know garbage collector works in .net there is something heap and stack funda.so can u please tell me from where i get reference of whole funda of that.and i have another question is that Please see below the code.here i declare one dt and get
some data in it.and i don't want that dt after data come in text boxes.so in finally method i do dispose using dt.dispoe().

but after that i write little code to check whether the dt correctly dispose or not.so i check with if condition after disposing.you can check code given below for that condition.as per condition it gives me "Nikunj" Ouput in message box it meanse dt is not disposed after calling the dispose method.so can u please tell me why?And i Want to know about all resources which i used i want to know how can i free it.whether it is variable,object,datatable,datareader etc..... if it is any where with example then please give me link.and if it's from msdn then it's better. i want to know from Microsoft that

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