There is LIRC data for a Bush 28" tv here
[Link: lirc.sourceforge.net]

If your TV has the same IR signals as that one, it is RC5 protocol (the most common protocol with a toggle bit) device 0.

It is easiest to define RC5 codes using the "Define RC5/6" dialog, which you can reach from the "Advanced" button of the "add IR" dialog.

Select RC5 (rather than RC5x or RC6)
Set the "System" to 0.
Use a hex calculator (such as windows calculator view/scientific) to translate the rightmost 2 digits of each function number from that LIRC data from hex to decimal, then enter it as the "Command" in the "Define RC5/6" dialog. That should work for everything there except menu-off and zoom, which need to be 64 greater than the value of translating the hex to decimal.