diff --git a/erpnext/hr/doctype/salary_detail/salary_detail.json b/erpnext/hr/doctype/salary_detail/salary_detail.json
index 3bb621b..99c705a 100644
--- a/erpnext/hr/doctype/salary_detail/salary_detail.json
+++ b/erpnext/hr/doctype/salary_detail/salary_detail.json
@@ -300,7 +300,7 @@
    "label": "Condition and Formula Help", 
    "length": 0, 
    "no_copy": 0, 
-   "options": "<h3>Condition and Formula Help</h3>\n\n<p>Notes:</p>\n\n<ol>\n<li>Use field <code>base</code> for using base salary of the Employee</li>\n<li>Use Salary Component abbreviations in conditions and formulas. <code>BS = Basic Salary</code></li>\n<li>Use field name for employee details in conditions and formulas. <code>Employment Type = employment_type</code><code>Branch = branch</code></li>\n<li>Direct Amount can also be entered based on Condtion. See example 3</li></ol>\n\n<h4>Examples</h4>\n<ol>\n<li>Calculating Basic Salary based on <code>base</code>\n<pre><code>Condition: base &lt; 10000</code></pre>\n<pre><code>Formula: base * .2</code></pre></li>\n<li>Calculating HRA based on Basic Salary<code>BS</code> \n<pre><code>Condition: BS &gt; 2000</code></pre>\n<pre><code>Formula: BS * .1</code></pre></li>\n<li>Calculating TDS based on Employment Type<code>employment_type</code> \n<pre><code>Condition: employment_type==\"Intern\"</code></pre>\n<pre><code>Amount: 1000</code></pre></li>\n</ol>", 
+   "options": "<h3>Condition and Formula Help</h3>\n\n<p>Notes:</p>\n\n<ol>\n<li>Use field <code>base</code> for using base salary of the Employee</li>\n<li>Use Salary Component abbreviations in conditions and formulas. <code>BS = Basic Salary</code></li>\n<li>Use field name for employee details in conditions and formulas. <code>Employment Type = employment_type</code><code>Branch = branch</code></li>\n<li>Use field name from Salary Slip in conditions and formulas. <code>Payment Days = payment_days</code><code>Leave without pay = leave_without_pay</code></li>\n<li>Direct Amount can also be entered based on Condtion. See example 3</li></ol>\n\n<h4>Examples</h4>\n<ol>\n<li>Calculating Basic Salary based on <code>base</code>\n<pre><code>Condition: base &lt; 10000</code></pre>\n<pre><code>Formula: base * .2</code></pre></li>\n<li>Calculating HRA based on Basic Salary<code>BS</code> \n<pre><code>Condition: BS &gt; 2000</code></pre>\n<pre><code>Formula: BS * .1</code></pre></li>\n<li>Calculating TDS based on Employment Type<code>employment_type</code> \n<pre><code>Condition: employment_type==\"Intern\"</code></pre>\n<pre><code>Amount: 1000</code></pre></li>\n</ol>", 
    "permlevel": 0, 
    "precision": "", 
    "print_hide": 0, 
@@ -323,7 +323,7 @@
  "issingle": 0, 
  "istable": 1, 
  "max_attachments": 0, 
- "modified": "2016-08-23 15:26:07.754570", 
+ "modified": "2016-09-20 05:29:26.373992", 
  "modified_by": "Administrator", 
  "module": "HR", 
  "name": "Salary Detail", 
diff --git a/erpnext/hr/doctype/salary_slip/salary_slip.py b/erpnext/hr/doctype/salary_slip/salary_slip.py
index 1918f92..dbbdf7f 100644
--- a/erpnext/hr/doctype/salary_slip/salary_slip.py
+++ b/erpnext/hr/doctype/salary_slip/salary_slip.py
@@ -31,7 +31,7 @@
 			self.get_leave_details(lwp = self.leave_without_pay)
 
 		# if self.salary_slip_based_on_timesheet or not self.net_pay:
-		# 	self.calculate_net_pay()
+		self.calculate_net_pay()
 
 		company_currency = get_company_currency(self.company)
 		self.total_in_words = money_in_words(self.rounded_total, company_currency)
@@ -52,15 +52,27 @@
 
 		data = self.get_data_for_eval()
 		for key in ('earnings', 'deductions'):
-			for d in self._salary_structure_doc.get(key):
-				amount = self.eval_condition_and_formula(d, data)				
-				if amount:
-					self.append(key, {
-						'amount': amount,
-						'default_amount': amount,
-						'depends_on_lwp' : d.depends_on_lwp,
-						'salary_component' : d.salary_component
-					})
+			for struct_row in self._salary_structure_doc.get(key):
+				amount = self.eval_condition_and_formula(struct_row, data)	
+					if amount:
+						self.update_component_row(struct_row, amount, key)
+					
+					
+	def update_component_row(self, struct_row, amount, key):
+		component_row = None
+		for d in self.get(key):
+			if d.salary_component == struct_row.salary_component:
+				component_row = d
+		
+		if not component_row:
+			self.append(key, {
+				'amount': amount,
+				'default_amount': amount,
+				'depends_on_lwp' : struct_row.depends_on_lwp,
+				'salary_component' : struct_row.salary_component
+			})
+		else:
+			component_row.amount = amount
 	
 	def eval_condition_and_formula(self, d, data):
 		try:
@@ -74,6 +86,7 @@
 					amount = eval(d.formula, None, data)
 	
 				data[d.abbr] = amount
+
 			return amount
 		except NameError as err:
 		    frappe.throw(_("Name error: {0}".format(err)))
@@ -92,6 +105,7 @@
 				data.base, data.variable = d.base, d.variable
 	
 		data.update(frappe.get_doc("Employee", self.employee).as_dict())
+		data.update(self.as_dict())
 
 		# set values for components
 		salary_components = frappe.get_all("Salary Component", fields=["salary_component_abbr"])
@@ -351,4 +365,4 @@
 				timesheet.salary_slip = salary_slip
 				timesheet.flags.ignore_validate_update_after_submit = True
 				timesheet.set_status()
-				timesheet.save()
\ No newline at end of file
+				timesheet.save()