design and implementation of microstrip coupled line filters

hello....
we want 2 design n implement microstrip coupled line filters with d help of ie3d software....
but we have no idea about dis software....
plz tel us how 2 find out required parameters n what r those parameters?
first tell us about in case of designing low pass coupled line filters....
plzzzz rpy if any1 knows abt it........
plzz rpy as soon as posible........