I am using a Creda Capri hotplate hob (possibly this one [pdf]).  The problem is the area around the burners has became too dirty, with sticky burns. Here's a photo:    I have tried using Dettol Spray Power And Pure Kitchen but was unable to remove the stains. What I can do? 
Pour vinegar on it leave for 5 mins. Then add table salt. Leave to soak and then gently rub it off. Repeat until it comes up clean. You can also use bicarbonate of soda with the salt if it does not come up clean. 