clio wont start

i have a 1.4s clio w reg the car wont start the light on dash just keeps flashing and the engine just turns over,
if i get a key guy out to put a 4 digit code in with his machine it will start up straight away but the day after it wont start just turns overs again if he puts the code in again it will start again anyone any ideas

sound like the code is not saving

Does your central locking work via your key??

Because as well as what nellybob said "the code isnt saving" it also could be that your key isnt sending a signal through to your immobiser...

if you have a spare key, give that a bash. if not, try getting a new battery on ebay.

good luck