cheats

How do you get the cheats to work on this?
I got them to work on the first one but i cant get them to work on this,whenever i try adding console to properties i get this message............
'The name'C/Program Files/Half-Life 2/hl2.exe"-console specified in the target box is not valid. Make sure the path and file name are correct

I have no idea what this means but its drivinng me insane,any help anyone??
cheers