Create Custom error Page

I want if any  error come in my application it goes to an custom error page, take its description  and return back to first parent function and show error here.

I mean, we have four functions FunA, FunB, FunC, FunD - The FunB call from FunA, FuncC call from FunB & FunD call from FunC and if any error come in FunD, then it get error description from Custom class and directly return back to its first parent function (FunA)  and show error description without going through FunC & then FubB. In the same way if FunB is a first parent page and error come in FunD then after getting error description from Custom Class, return back to first parent FunB. 
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