Hi Ram,
If you have ANT in your C:\ folder (in case of WINDOW);
say C:\ANT1.6.1 . Then in path varible you must specify
PATH=%PATH%;C:\ANT1.6.1\BIN
And no doubt you need to have set JAVA_HOME too.
Say if you have
java installed in C:\j2sdk1.4.2_04, then should have set JAVA_HOME environment varible to C:\j2sdk1.4.2_04\bin .
Hope it may help you !