c# - WebException Response attribute returns null -

i'm scanning single url has many paths example: http://url.com/path1 1000. webexception in catch block, throw nullreferenceexception error if don't use line
if (x.status == webexceptionstatus.protocolerror && x.response != null)

so question this: code below fix error or ignore it?

error don't have specific path error random http://url.com/path10 or other link :)

catch (webexception x) {     if (x.status == webexceptionstatus.protocolerror && x.response != null)     {         httpwebresponse response = (httpwebresponse)x.response;         if (response.statuscode == httpstatuscode.notfound)         {            listbox3.items.add(listbox1.items[i].tostring());         }     } } 

according documentation webexception.response property

if response available internet resource, webresponse instance contains error response internet resource; otherwise, null.

so, if understand question correctly, is necessary test webexception.response null, meaning code correctly avoids nullreferenceexception rather 'ignoring' it.

hope helps.