validation - Need to validate GXT DateFields dateTo must be older than dateFrom -

need validate gxt datefields dateto must older datefrom. i'm thinking solution problem should date validator created purpose.

any ideas, samples?

the solution problem here:

@uihandler("datefrom") void datefromchange(valuechangeevent<date> event){     datefrom.addvalidator(new maxdatevalidator(dateto.getvalue())); }