diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/Extensions.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/Extensions.java
index be445df53f..cc46b127e1 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/Extensions.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/Extensions.java
@@ -23,6 +23,8 @@ package org.adempiere.webui;
 import java.util.List;
 
 import org.adempiere.base.Service;
+import org.adempiere.base.ServiceQuery;
+import org.adempiere.webui.apps.IProcessParameterListener;
 import org.adempiere.webui.factory.IFormFactory;
 import org.adempiere.webui.panel.ADForm;
 
@@ -50,4 +52,18 @@ public class Extensions {
 		}
 		return null;
 	}
+	
+	/**
+	 * 
+	 * @param processClass
+	 * @param columnName
+	 * @return list of parameter listener
+	 */
+	public static List<IProcessParameterListener> getProcessParameterListeners(String processClass, String columnName) {
+		ServiceQuery query = new ServiceQuery();
+		query.put("ProcessClass", processClass);
+		if (columnName != null)
+			query.put("|ColumnName", columnName+"|"+columnName+",*|"+"*,"+columnName+",*|"+"*,"+columnName);
+		return Service.locator().list(IProcessParameterListener.class, null, query).getServices();
+	}
 }
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/IProcessParameterListener.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/IProcessParameterListener.java
new file mode 100644
index 0000000000..5ebe52790d
--- /dev/null
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/IProcessParameterListener.java
@@ -0,0 +1,40 @@
+/******************************************************************************
+ * Product: iDempiere ERP & CRM Smart Business Solution                       *
+ * Copyright (C) 1999-2018 iDempiere.org. All Rights Reserved.               *
+ * This program is free software; you can redistribute it and/or modify it    *
+ * under the terms version 2 of the GNU General Public License as published   *
+ * by the Free Software Foundation. This program is distributed in the hope   *
+ * that it will be useful, but WITHOUT ANY WARRANTY; without even the implied *
+ * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.           *
+ * See the GNU General Public License for more details.                       *
+ * You should have received a copy of the GNU General Public License along    *
+ * with this program; if not, write to the Free Software Foundation, Inc.,    *
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.                     *
+ *****************************************************************************/
+package org.adempiere.webui.apps;
+
+import org.adempiere.webui.editor.WEditor;
+
+/**
+ * Listener interface for process parameter panel
+ * @author hengsin
+ *
+ */
+public interface IProcessParameterListener {
+	/**
+	 * on value change of parameter field editor
+	 * @param parameterPanel
+	 * @param columnName
+	 * @param editor
+	 */
+	public void onChange(ProcessParameterPanel parameterPanel, String columnName, WEditor editor);
+	
+	/**
+	 * validate process parameter form
+	 * @param parameterPanel
+	 * @return error message (if any)
+	 */
+	public default String validate(ProcessParameterPanel parameterPanel) {
+		return null;
+	}	
+}
diff --git a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessParameterPanel.java b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessParameterPanel.java
index 3f7ef31270..6200efb58b 100644
--- a/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessParameterPanel.java
+++ b/org.adempiere.ui.zk/WEB-INF/src/org/adempiere/webui/apps/ProcessParameterPanel.java
@@ -23,6 +23,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.logging.Level;
 
+import org.adempiere.webui.Extensions;
 import org.adempiere.webui.component.Column;
 import org.adempiere.webui.component.Columns;
 import org.adempiere.webui.component.EditorBox;
@@ -50,12 +51,14 @@ import org.compiere.model.MClient;
 import org.compiere.model.MLookup;
 import org.compiere.model.MPInstance;
 import org.compiere.model.MPInstancePara;
+import org.compiere.model.MProcess;
 import org.compiere.process.ProcessInfo;
 import org.compiere.util.CLogger;
 import org.compiere.util.DB;
 import org.compiere.util.DisplayType;
 import org.compiere.util.Env;
 import org.compiere.util.Msg;
+import org.compiere.util.Util;
 import org.zkoss.zk.ui.Component;
 import org.zkoss.zk.ui.HtmlBasedComponent;
 import org.zkoss.zk.ui.event.Event;
@@ -99,6 +102,7 @@ public class ProcessParameterPanel extends Panel implements
 		//
 		initComponent();
 		addEventListener("onDynamicDisplay", this);
+		addEventListener("onPostEditorValueChange", this);
 	} // ProcessParameterPanel
 	
 	private void initComponent() {
@@ -445,6 +449,18 @@ public class ProcessParameterPanel extends Panel implements
 			return false;
 		}
 
+		if (m_processInfo.getAD_Process_ID() > 0) {
+			String className = MProcess.get(Env.getCtx(), m_processInfo.getAD_Process_ID()).getClassname();
+			List<IProcessParameterListener> listeners = Extensions.getProcessParameterListeners(className, null);
+			for(IProcessParameterListener listener : listeners) {
+				String error = listener.validate(this);
+				if (!Util.isEmpty(error)) {
+					FDialog.error(m_WindowNo, this, error);
+					return false;
+				}
+			}
+		}
+		
 		return true;
 	}	//	validateParameters
 	
@@ -703,6 +719,7 @@ public class ProcessParameterPanel extends Panel implements
 				processDependencies (changedField);
 				// future processCallout (changedField);
 			}
+			Events.postEvent("onPostEditorValueChange", this, evt.getSource());
 		}
 		processNewValue(evt.getNewValue(), evt.getPropertyName());
 	}
@@ -731,8 +748,21 @@ public class ProcessParameterPanel extends Panel implements
     	else if (event.getName().equals("onDynamicDisplay")) {
     		dynamicDisplay();
     	}
+    	else if (event.getName().equals("onPostEditorValueChange")) {
+    		onPostEditorValueChange((WEditor)event.getData());
+    	}
 	}
 
+	private void onPostEditorValueChange(WEditor editor) {
+		if (m_processInfo.getAD_Process_ID() > 0) {
+			String className = MProcess.get(Env.getCtx(), m_processInfo.getAD_Process_ID()).getClassname();
+			List<IProcessParameterListener> listeners = Extensions.getProcessParameterListeners(className, editor.getColumnName());
+			for(IProcessParameterListener listener : listeners) {
+				listener.onChange(this, editor.getColumnName(), editor);
+			}
+		}
+	}
+	
 	/**
 	 *  Evaluate Dependencies
 	 *  @param changedField changed field
@@ -874,6 +904,34 @@ public class ProcessParameterPanel extends Panel implements
 		((HtmlBasedComponent)c).focus();		
 	}
 	
+	/**
+	 * Get parameter field editor by column name
+	 * @param columnName
+	 * @return editor
+	 */
+	public WEditor getEditor(String columnName) {
+		for(int i = 0; i < m_mFields.size(); i++) {
+			if (m_mFields.get(i).getColumnName().equals(columnName)) {
+				return m_wEditors.get(i);
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Get parameter field value to editor by column name
+	 * @param columnName
+	 * @return editor
+	 */
+	public WEditor getEditorTo(String columnName) {
+		for(int i = 0; i < m_mFields.size(); i++) {
+			if (m_mFields.get(i).getColumnName().equals(columnName)) {
+				return m_wEditors2.get(i);
+			}
+		}
+		return null;
+	}
+	
 	static class ZoomListener implements EventListener<Event> {
 
 		private IZoomableEditor searchEditor;