Representation class for Equation constraint.
The equation constraint is supposed to be used whenever two values are to be compared. You have to give it the perl operator (ne, eq, <,>, whatever) and the two values to be compared via the params hash. Straight forward so no need for much documentation. See HTML::TurboForm doku for mopre details.
returns 1 if valid, otherwise 0.
returns Errormessage of Element which is connected to constraint.
Thorsten Domsch, email@example.com