Did yo bother with the other things "Good Luck" suggested?
1) You might try looking at the control's output through a digital camera or mobile phone to check if anything's coming out.
2) You might try selecting the function you need using the TV's built-in control buttons.
To which I could add:
If the remiote isn't transmitting anything when you press the Menu or Internet buttons, you could just try to get a new remote. Thre should be plenty on EBay, but you will need more than "Panasonic" to describe the remote you need. You will have to find out the model number of your set EVEN IF IT MEANS DOING THAT FOR YOURSELF
Travor, May 2016
panasonic have changed the batteries ,changed the remote,one day it was working the next day it comes up with no internet connection ,but as i can not access my menu button i can not gain access to anything
kevin, May 2016
You do not mention the make or model of the TV but no matter - Either the Remote control is not sending the request -OR- the TV is not seeing the request -OR- The TV is not properly decoding the request.
You might try new batteries in the remote control - you might try looking at the control's output through a digital camera or mobile phone to check if anything's coming out. You might try selecting the function you need using the TV's built-in control buttons. You might try having a specialist look at your configuration. You might try using another remote control - Amazon sell them I believe.