The Parameter and the input control need to have the same name: in this case it seems to be 'client'. I am not entirely sure if you need the locale paremeter as the JRXML has a parameter REPORT_LOCALE which is filled by the environment, such as iReport or JasperServer. the syntax using the ! is only if you are injecting code into the report query. please share the querystring, parameter definition and details about the input control.