Employee can be reselected but not changed in salary structure
diff --git a/erpnext/hr/doctype/salary_structure/salary_structure.js b/erpnext/hr/doctype/salary_structure/salary_structure.js
index ee42d0c..ddaf88c 100644
--- a/erpnext/hr/doctype/salary_structure/salary_structure.js
+++ b/erpnext/hr/doctype/salary_structure/salary_structure.js
@@ -14,8 +14,6 @@
 	if((!doc.__islocal) && (doc.is_active == 'Yes')){
 		cur_frm.add_custom_button(__('Make Salary Slip'), cur_frm.cscript['Make Salary Slip']);
 	}
-
-	cur_frm.toggle_enable('employee', doc.__islocal);
 }
 
 cur_frm.cscript['Make Salary Slip'] = function() {
diff --git a/erpnext/hr/doctype/salary_structure/salary_structure.py b/erpnext/hr/doctype/salary_structure/salary_structure.py
index f3d2eb1..97935e6 100644
--- a/erpnext/hr/doctype/salary_structure/salary_structure.py
+++ b/erpnext/hr/doctype/salary_structure/salary_structure.py
@@ -54,18 +54,28 @@
 	def check_existing(self):
 		ret = frappe.db.sql("""select name from `tabSalary Structure` where is_active = 'Yes'
 			and employee = %s and name!=%s""", (self.employee,self.name))
+
 		if ret and self.is_active=='Yes':
-			frappe.throw(_("Another Salary Structure {0} is active for employee {0}. Please make its status 'Inactive' to proceed.").format(cstr(ret), self.employee))
+			frappe.throw(_("Another Salary Structure {0} is active for employee {1}. Please make its status 'Inactive' to proceed.").format(cstr(ret[0][0]), self.employee))
 
 	def validate_amount(self):
 		if flt(self.net_pay) < 0:
 			frappe.throw(_("Net pay cannot be negative"))
 
+	def validate_employee(self):
+		old_employee = frappe.db.get_value("Salary Structure", self.name, "employee")
+		print old_employee
+		if old_employee and self.employee != old_employee:
+			frappe.throw(_("Employee can not be changed"))
+
+
 	def validate(self):
 		self.check_existing()
 		self.validate_amount()
+		self.validate_employee()
 		set_employee_name(self)
 
+
 @frappe.whitelist()
 def make_salary_slip(source_name, target_doc=None):
 	def postprocess(source, target):