In JSP File:

<script src="<openmrs:contextPath/>/dwr/interface/DWRAppointmentService.js"></script>
<script type="text/javascript">
   function updatePatient(formFieldId, patientObj, isPageLoad) {
	if(!isPageLoad){
		DWRAppointmentService.getPatientDescription(patientObj.patientId, function(details){
			if(details==null){
				document.getElementById('labelPhone').value = "";
				document.getElementById('labelMissed').value = "";
			}
			else{
				if(details[0]!=null)
					document.getElementById('labelPhone').value = details[0];
				if(details[1]!=null)
					document.getElementById('labelMissed').value = details[1];
			}
		});
	}
   }
</script>

In DWRAppointmentService Class

public class DWRAppointmentService {

	public PatientDescription getPatientDescription(Integer patientId) {
		Patient patient = Context.getPatientService().getPatient(patientId);
		if (patient == null)
			return null;

		PatientDescription patientDescription = new PatientDescription("test","test");
		/*patientDescription
		        .setPhoneNumber(patient.getAttribute(
		            Context.getAdministrationService().getGlobalProperty("appointment.phoneNumberPersonAttributeTypeId"))
		                .getValue());
		Date missedLastAppointment = Context.getService(AppointmentService.class).getMissedLastAppointment(patient);
		if (missedLastAppointment != null)
			patientDescription.setDateMissed(Context.getDateFormat().format(missedLastAppointment));
		*/
		return patientDescription;
	}
}

In config.xml

<dwr>
		<allow>
			<create creator="yony258" javascript="DWRAppointmentService">
				<param name="class" value="@MODULE_PACKAGE@.web.DWRAppointmentService" />
				<include method="getPatientDescription" />
			</create>
		</allow>

		<signatures>
            <![CDATA[
            import @MODULE_PACKAGE@.web.DWRAppointmentService;
            DWRAppointmentService.getPatientDescription(Integer patientId);
            ]]>
		</signatures>
	</dwr>