make a simple alarm

hi everyone could anyone tell me the best way to make a simple alarm for my shed using 2 arduino's
simple as if some one breaks in it triggers the other arduino to make a buzzer work
ether bluetooth or 433mhz transmitter and reciver
cheers for any help

If you are putting one in the shed and one in your house I would use a JeeNode.
JeeNode is a small Arduino with a radio built in. Very easy to use.

I use 2 for my weather station.

http://moderndevice.com/product/jeenode-v6-kit/

yes one in the shed and the other in the house
so it can be portable im using 2 nano's

The buzzer part is probably easiest.
I think the first step is to define what you mean by break in.
Does that mean a window is broken, a door opened or are something else?

lets say if using a reed switch ether the circuit is made or broken that it will let the other arduino know somthing has changed .
so emitting a signal to other arduino to let it know

Well, you could try using a Nano with an Xbee.
You would need two of them, one for sending and one for receiving.
This board seems to make connecting them easier. http://www.robotshop.com/en/arduino-nano-xbee-board.html

Here is an Xbee that Adafruit sells. XBee Module - Series 1 - 1mW with Wire Antenna [XB24-AWI-001] : ID 128 : $22.95 : Adafruit Industries, Unique & fun DIY electronics and kits

One other thing to consider is how far away the shed is from your house.

Frankly, I find using JeeNodes easier than Xbees, but that is me.

the shed is only 20 meters away