Custom script regarding attendance sheet

I am new to frappe.I am developing attendance sheet. so developed child table called vidyarthi where name,roll no,mob no are stored.Later i linked it with another doctype attendance sheet.

i found error as
frappe/css/octicons/octicons.ttf
VM152:19 triggered
jquery.min.js:4 GET https://dev.selcoerp.com/?doctype=vidyarthi&name=vidyarthi&cmd=frappe.desk.form.load.getdoc&_=1510153658927 404 (NOT FOUND)
send @ jquery.min.js:4
ajax @ jquery.min.js:4
frappe.request.call @ desk.min.js:139
frappe.call @ desk.min.js:135
with_doc @ desk.min.js:557
refresh @ VM152:20
(anonymous) @ form.min.js:260
(anonymous) @ form.min.js:260
map @ jquery.min.js:2
trigger @ form.min.js:260
_f.Frm.render_form @ form.min.js:67
(anonymous) @ form.min.js:77
(anonymous) @ form.min.js:260
map @ jquery.min.js:2
trigger @ form.min.js:260
f.Frm.setnewdoc @ form.min.js:77
f.Frm.refresh @ form.min.js:58
load @ form.min.js:15
(anonymous) @ form.min.js:13
callback @ desk.min.js:557
callback @ desk.min.js:134
200 @ desk.min.js:136
(anonymous) @ desk.min.js:141
i @ jquery.min.js:2
fireWith @ jquery.min.js:2
z @ jquery.min.js:4
(anonymous) @ jquery.min.js:4
XMLHttpRequest.send (async)
send @ jquery.min.js:4
ajax @ jquery.min.js:4
frappe.request.call @ desk.min.js:139
frappe.call @ desk.min.js:135
with_doc @ desk.min.js:557
show_doc @ form.min.js:13
(anonymous) @ form.min.js:10
callback @ desk.min.js:554
callback @ desk.min.js:134
200 @ desk.min.js:136
(anonymous) @ desk.min.js:141
i @ jquery.min.js:2
fireWith @ jquery.min.js:2
z @ jquery.min.js:4
(anonymous) @ jquery.min.js:4
XMLHttpRequest.send (async)
send @ jquery.min.js:4
ajax @ jquery.min.js:4
frappe.request.call @ desk.min.js:139
frappe.call @ desk.min.js:135
with_doctype @ desk.min.js:551
make @ form.min.js:10
show @ desk.min.js:896
frappe.route @ desk.min.js:184
startup @ desk.min.js:1053
load_startup @ desk.min.js:1052
init @ desk.min.js:1052
Class @ desk.min.js:7
frappe.start_app @ desk.min.js:1051
(anonymous) @ desk.min.js:1052
i @ jquery.min.js:2
fireWith @ jquery.min.js:2
ready @ jquery.min.js:2
J @ jquery.min.js:2
desk.min.js:151 Traceback (most recent call last):
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/desk/form/load.py”, line 32, in getdoc
doc = frappe.get_doc(doctype, name)
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/init.py”, line 597, in get_doc
return frappe.model.document.get_doc(arg1, arg2)
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/model/document.py”, line 50, in get_doc
return controller(arg1, arg2)
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/model/document.py”, line 83, in init
self.load_from_db()
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/model/document.py”, line 114, in load_from_db
frappe.throw(
("{0} {1} not found").format(
(self.doctype), self.name), frappe.DoesNotExistError)
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/init.py”, line 310, in throw
msgprint(msg, raise_exception=exc, title=title, indicator=‘red’)
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/init.py”, line 303, in msgprint
_raise_exception()
File “/home/basawaraj/frappe-bench/apps/frappe/frappe/init.py”, line 276, in _raise_exception
raise raise_exception, encode(msg)
DoesNotExistError: vidyarthi vidyarthi not found
.
I used script as

frappe.ui.form.on("attendance sheet", {
	"refresh": function(frm) {
		console.log("triggered");
		frappe.model.with_doc("vidyarthi", frm.doc.refresh, function() {
			var tabletransfer= frappe.model.get_doc("vidyarthi", frm.doc.refresh)
			$.each(tabletransfer.student_name, function(index, row){
				d = frm.add_child("student_name");
				d.student_name = row.student_name;

				frm.refresh_field("student_name");
			});
		});
	}
});

Kindly help me in this regard