Adding a new child table row in another document

Can you guys help me achieve this . I want to add child table rows in another document ,this document will be found as a result of frappe call . Below is the script which i have written which is not working. Can someone help me
frappe.call
({
“method”:“frappe.client.get”,
“args”:
{
“doctype”:“Timesheet”,
“filters”:
{
// filters
},
},
callback:function(r)
{
if(r)
{
frm.add_child(‘r.message.time_logs’).field_name=“Value”
frm.refresh_field(‘r.message.time_logs’);
}
}
});