can't use delete [1]

At Xshell 3.0 when i using sqlplus , can't use delete key .

using delete and <-key,as follows :

SQL> conn^[[3~^[[3~^[[3~^H^H^H^H^H^H

but when i using SecureCRT at she same environment, everything is ok.

The Terminal Type is vt100

Program Ver. : Xshell 3.0

Try changin the delete key sequence to ASCII 127 in the session properties (terminal > keyboard).