How to Ant Environment path set in mac

I am working in phonegap application. when i want to develop phonegap android blatform i want to set ant build path as environment variable. I tried various way to export the path. but i can't correctly set the ant both and then my friend referred just like this

Apples-MacBook-Pro:bin apple$ ant
-bash: ant: command not found
Apples-MacBook-Pro:bin apple$ cd
Apples-MacBook-Pro:~ apple$ which ant
Apples-MacBook-Pro:~ apple$ cd Documents/apache-ant-1.9.4/bin
Apples-MacBook-Pro:bin apple$ export PATH=$PATH:$PWD
Apples-MacBook-Pro:bin apple$ ant
Buildfile: build.xml does not exist!
Build failed
Apples-MacBook-Pro:bin apple$ cd
Apples-MacBook-Pro:~ apple$ ant
Buildfile: build.xml does not exist!
Build failed
Apples-MacBook-Pro:~ apple$ 

just try like this you can set easy.