The alarm clock on S5230 soemtimes work and sometimes it doesnot work, please help

Here's how you do it:
Menu--Alarms--Tap to create--Alarm Name and Alarm Time [the time you want the alarm to go off] (I'm sure you can fill that up)--Now here is the part where you are facing the issue--The Alarm Repeat--Now press the Week days Tab--Select Everyday if you want the alarm to repeat everyday or select alternate days--Click Save.
Now the alarm will go off according to your set schedule.

If you need more help on that do let me know.

At alarm repeat please select" only once" then try..i have just tried it and found it worked.