call2rb

Can you help me understand this script a little bit more? mainly the part below. I understand online and offline but what does the last one mean Unknown host (no DNS entry? If InStr(temp, "Reply from") Then ofile.writeline item & ","&strip&","&"Online." ElseIf InStr(temp, "Request timed out.") Then ofile.writeline item &","&strip&","&"No response (Offline)." ELSEIf InStr(temp, "try again") Then ofile.writeline item & ","&strip&","&"Unknown host (no DNS entry)."