please let me know any thing worng in my script becuase i didn't get user_sesstion1 result

[mani55]

api.controller=function($scope,$rootScope,spSCNavStateManager,spUtil) {
  /* widget controller */
  var c = this;
  var min = 1 ;
  var max = '';	
	//$scope.request_type = $scope.page.g_form.getValue('request_type_txt')+'';	
		
	c.server.update().then(function(res){		
			$rootScope.$on("field.change", function(evt, parms) {
				
				var no_of_vdi = $scope.page.g_form.getIntValue('user_session');
			//	var no_of_users = $scope.page.g_form.getIntValue('noofusers');
				//var number_vdi = $scope.page.g_form.getIntValue('No_of_VDI');
		
      //###################################################################
					if (parms.field.name == 'user_session1'){
					var vdi_value =  $scope.page.g_form.getValue('user_session1');	
					if (vdi_value == '') 					
						$scope.page.g_form.setValue('enter_license_count','');		
				}
								
				if(parms.field.name == 'modify_licenses_count' || parms.field.name == 'enter_license_count' ) {
					var value_vdi=	$scope.page.g_form.getDisplayValue('modify_licenses_count');
					var add_vdi= $scope.page.g_form.getIntValue('enter_license_count');				
                    $scope.page.g_form.setValue('user_session1',no_of_vdi);
					
					if(value_vdi =='add_licenses')
					{
						if(parms.field.name == 'modify_licenses_count' || add_vdi > 0) {							
							$scope.page.g_form.setValue('user_session1',no_of_vdi  + add_vdi);
					}
					else 		
                        {
						$scope.page.g_form.clearValue('enter_license_count');
				$scope.page.g_form.showFieldMsg('enter_license_count','The maximum number of Users/device per service is 10 currently.','error');
						}
					}
                   if(value_vdi == 'remove_licenses')
                    {
                      if(parms.field.name == 'modify_licenses_count' || add_vdi > 0)  {
							$scope.page.g_form.setValue('user_session1',no_of_vdi  - add_vdi);
                       }
					else 		
                        {
						$scope.page.g_form.clearValue('enter_license_count');
				$scope.page.g_form.showFieldMsg('enter_license_count','The service should have minimum 1 user/device in active state. To remove all users/devices, you need to retire the service','error');
						}	
                    }
				}}
			)})};