Thanks everyone, ron your a legend thats exactly what i was thinking of, i tested it with just a 6v battery setup and it worked then i took that into excel and created a graph just like i wanted.
Now to work out the schematic to my needs.
Just a few questions.
Is the light sensor on the schematic a photo-sensor, i do have one from a old tv ir receiver, would that suit or is it like a sensor you would find in a day . night light?
Q2. What would be the configuration for the resistors to suit as i would want it to just trigger instant but believe the setup is for 10 second pulse.
Q3, it also said on the forum for the schematic that there is resistors for light filters, what would i need for a just a laser so the daylight / night light wouldn't effect it.
Q4. im thinking im correct in thinking the + of buzzer is pin8 and buzzer negatime is pin 5.
Thanks again. almost there......