question about adding an additional head

[ga1990]

So what I have is a landscaped area about 15 feet wide that has one sprinkler head in it. What I'm doing is adding a tier to the existing retaining wall (shown in red)just to the right of where the head is. The second tier will be about 2 feet higher than the current level. So my question is, can I just put a tee in where the current head is and then put 1 head each in the lower and upper tier (where the red X's are)? I've never worked with irrigation systems before but am familiar with plumbing in general. Thank you for your help.
http://img.villagephotos.com/p/2008-2/1300546/spinkler3.JPG

[mitchgo]

As long as your zone isn't over extended and you have enough water flow and pressure to supply the head then sure.
It's not the best way to do it but it works.
You will most likely have to change the nozzle design as well.
I recommend two End Stripes