Editable Grid SAIL

I tried the following SAIL recipe which worked well with Employees CDT as ri! parameter for adding rows. I thought deletion would also be done by the same call using write to datastore smart service in a kind of merging but it did not. I am trying to call another service for deletion with deleted ids stored in another ri! parameter. However I am getting into following two issues.

1) The deleted id is +1 more than rowid

2) When submit button is pressed I am getting error that my deleted ids array is null. 

Could somebody provide me details on what needs to be done?

=load(
a!formLayout(
label: "SAIL Example: Add,Update, or Remove Employee Data",
contents: {
a!gridLayout(
totalCount: count(ri!Employees),
headerCells: {
a!gridLayoutHeaderCell(label: "id" ),
a!gridLayoutHeaderCell(label: "First Name" ),
a!gridLayoutHeaderCell(label: "Last Name" ),
a!gridLayoutHeaderCell(label: "Department" ),
a!gridLayoutHeaderCell(label: "Title" ),
a!gridLayoutHeaderCell(label: "Phone Number" ),
a!gridLayoutHeaderCell(label: "Start Date", align: "RIGHT" ),
/* For the "Remove" column */
a!gridLayoutHeaderCell(label: "" )
},
/* Only needed when some columns need to be narrow */
columnConfigs: {
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:3 ),
a!gridLayoutColumnConfig(width: "DISTRIBUTE", weight:2 ),
a!gridLayoutColumnConfig(width: "ICON")
},
rows: a!forEach(
items: ri!Employees,
expression: a!gridRowLayout(
contents: {
a!integerField(
/* Labels are not visible in grid cells but are necessary to meet accessibility requirements */
label: "first name " & fv!index,
value: fv!item.id,
saveInto: fv!item.id,
required: true
),
/* For the First Name Column*/
a!textField(
/* Labels are not visible in grid cells but are necessary to meet accessibility requirements */
label: "first name " & fv!index,
value: fv!item.firstName,
saveInto: fv!item.firstName,
required: true
),
/* For the Last Name Column*/
a!textField(
label: "last name " & fv!index,
value: fv!item.lastName,
saveInto: fv!item.lastName,
required:true
),
/* For the Department Column*/
a!dropdownField(
label: "department " & fv!index,
placeholderLabel: "-- Select -- ",
choiceLabels: { "Corporate", "Engineering", "Finance", "Human Resources", "Professional Services", "Sales" },
choiceValues: { "Corporate", "Engineering", "Finance", "HR", "Professional Services", "Sales" },
value: fv!item.department,
saveInto: fv!item.department,
required:true
),
/* For the Title Column*/
a!textField(
label: "title " & fv!index,
value: fv!item.title,
saveInto: fv!item.title,
required:true
),
/* For the Phone Number Column*/
a!textField(
label: "phone number " & fv!index,
placeholder:"123-456-7890",
value: fv!item.phoneNumber,
saveInto: fv!item.phoneNumber
),
/* For the Start Date Column*/
a!dateField(
label: "start date " & fv!index,
value: fv!item.startDate,
saveInto: fv!item.startDate,
required:true,
align: "RIGHT"
),
/* For the Removal Column*/
a!imageField(
label: "delete " & fv!index,
images: a!documentImage(
document: a!iconIndicator("REMOVE"),
altText: "Remove Employee",
caption: "Remove " & fv!item.firstName & " " & fv!item.lastName,
link: a!dynamicLink(
value: fv!index,
saveInto: {
a!save(ri!Employees, remove(ri!Employees, save!value)),
a!save(ri!DeletedEmployees, append(ri!DeletedEmployees, fv!item.id))  -- ( fv!item.id -1 works logging in correct ids in to array for deletion)
}
)
),
size: "ICON"
)
},
id: fv!index
)
),
addRowlink: a!dynamicLink(
label: "Add Employee",
/*
* For your use case, set the value to a blank instance of your CDT using
* the type constructor, e.g. type!Employee(). Only specify the field
* if you want to give it a default value e.g. startDate: today()+1.
*/
value: 'type!{urn:com:appian:types}Employee'(),
saveInto: {
a!save(ri!Employees, append(ri!Employees,save!value))
}
)
)
},
buttons: a!buttonLayout(
primaryButtons: a!buttonWidgetSubmit(
label: "Submit",
saveInto:{ a!writeToDataStoreEntity(
dataStoreEntity: cons!DS_ENTITY_REF_EMPLOYEE,
valueToStore: ri!Employees
),
a!deleteFromDataStoreEntities(
entity: cons!DS_ENTITY_REF_EMPLOYEE,              -- This failes
identifiers: ri!DeletedEmployees
)
}
)
)
)
)