Square root function in calculator

[nemo]

I am trying to make a simple GUI based calculator for my homework.
my +,-,*, and sqr functions work fine. i have to implement sqrt function for one of my JButton.

am trying but have no clue what to put in event handler here

else if(event.getSource() == sqrt) {
.......
}

can someone enlighten me please.

nemo

[peter_budo]

java.lang.Math
http://java.sun.com/javase/6/docs/api/java/lang/Math.html#pow(double,%20double )

Hope it does not requere any comment