How do I use the "like" operator in Crystal Reports 2008 using a parameter -

How do I use the "like" operator in Crystal Reports 2008 using a parameter -

i trying create formula based on parameter allow user select description of supply item, or if none selected pull values. want able give them parameter allows them type part of description using "like" option. can first part of formula work not sec part. correctly pulling typed in item or if none typed returns values. past first "or" not work. should create seperate parameter sec part or can utilize same one?

if hasvalue ({?descr}) then{command.description} = {?descr} else true or ( upper({command.description}) "*" + uppercase({?descr}) + "*") or ( upper({command.description}) "*" + uppercase({?descr}) + "*")

to extent understand requirement don't need after if because though give single character or string hasvalue ({?descr}) returns true... hence can modify formula

if hasvalue ({?descr}) then{command.description} "*" + {?descr} + "*" else true

you can utilize uppercase if need.

edit:

if hasvalue ({?descr}) {command.description} "*" + {?descr} + "*" else if hasvalue({?niin}) {command.niin} = {?niin} else if hasvalue({?class}) {command.class} = {?class} else true

crystal-reports like crystal-reports-2008 formulas