How can I stop the accenta/optima G3 from sounding?

yes i have an optima people in my house turn the entire electric off in my garage and then the battery dies well what i do is put it on it sounds inside outside then i put the code in and then it says day and power green and red well because youve took the cover off you will need to power it up by battery first leave it for 5 mins but as soon as you put the battery in and the alarm sounds put youre code in if it works then tamper will be flashing press reset then tamper will be lit on a still light put the cover back on and then tamper wont be on then after that put the mains back on and it should be fine if the code does not accept these number may do it 9999 0123 or 0000 thanks

death
August 2009