diff --git a/main/src/com/google/refine/expr/functions/html/InnerHtml.java b/main/src/com/google/refine/expr/functions/html/InnerHtml.java
index 5ccafdc6b..5e9853d46 100644
--- a/main/src/com/google/refine/expr/functions/html/InnerHtml.java
+++ b/main/src/com/google/refine/expr/functions/html/InnerHtml.java
@@ -48,7 +48,7 @@ public class InnerHtml implements Function {
 
     @Override
     public Object call(Properties bindings, Object[] args) {
-        if (args.length >= 1) {
+        if (args.length == 1) {
             Object o1 = args[0];
             if (o1 != null && o1 instanceof Element) {
                 return new InnerXml().call(bindings, args, "html");
@@ -56,7 +56,7 @@ public class InnerHtml implements Function {
                 return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " failed as the first parameter is not an HTML Element.  Please first use parseHtml(string) and select(query) prior to using this function");
             }
         }
-        return null;
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a single String as an argument");
     }
 
 
diff --git a/main/src/com/google/refine/expr/functions/html/ParseHtml.java b/main/src/com/google/refine/expr/functions/html/ParseHtml.java
index 28bf387eb..14ae4b3cd 100644
--- a/main/src/com/google/refine/expr/functions/html/ParseHtml.java
+++ b/main/src/com/google/refine/expr/functions/html/ParseHtml.java
@@ -37,7 +37,6 @@ import java.util.Properties;
 
 import org.json.JSONException;
 import org.json.JSONWriter;
-import org.jsoup.Jsoup;
 
 import com.google.refine.expr.EvalError;
 import com.google.refine.expr.functions.xml.ParseXml;
diff --git a/main/src/com/google/refine/expr/functions/xml/OwnText.java b/main/src/com/google/refine/expr/functions/xml/OwnText.java
index b4df9c6d1..8066b9473 100644
--- a/main/src/com/google/refine/expr/functions/xml/OwnText.java
+++ b/main/src/com/google/refine/expr/functions/xml/OwnText.java
@@ -47,17 +47,17 @@ public class OwnText implements Function {
 
     @Override
     public Object call(Properties bindings, Object[] args) {
-        if (args.length >= 1) {
+        if (args.length == 1) {
             Object o1 = args[0];
             if (o1 != null && o1 instanceof Element) {
                 Element e1 = (Element)o1;
                 return e1.ownText();
 
             }else{
-                return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " failed as the first parameter is not an HTML Element.  Please first use parseHtml(string) and select(query) prior to using this function");
+                return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " failed as the first parameter is not an XML or HTML Element.  Please first use parseHtml(string) and select(query) prior to using this function");
             }
         }
-        return null;
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a single XML or HTML element as an argument");
     }
 
 
diff --git a/main/src/com/google/refine/expr/functions/xml/XmlAttr.java b/main/src/com/google/refine/expr/functions/xml/XmlAttr.java
index 269cb6796..c4746038d 100644
--- a/main/src/com/google/refine/expr/functions/xml/XmlAttr.java
+++ b/main/src/com/google/refine/expr/functions/xml/XmlAttr.java
@@ -47,7 +47,7 @@ public class XmlAttr implements Function {
 
     @Override
     public Object call(Properties bindings, Object[] args) {
-        if (args.length >= 2) {
+        if (args.length == 2) {
             Object o1 = args[0];
             Object o2 = args[1];
             if (o1 != null && o1 instanceof Element) {
@@ -59,7 +59,7 @@ public class XmlAttr implements Function {
                 return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " failed as the first parameter is not an XML or HTML Element.  Please first use parseXml() or parseHtml() and select() prior to using this function");
             }
         }
-        return null;
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects two arguments");
     }
 
 
diff --git a/main/src/com/google/refine/expr/functions/xml/XmlText.java b/main/src/com/google/refine/expr/functions/xml/XmlText.java
index 90dd0fa41..014eb8016 100644
--- a/main/src/com/google/refine/expr/functions/xml/XmlText.java
+++ b/main/src/com/google/refine/expr/functions/xml/XmlText.java
@@ -47,7 +47,7 @@ public class XmlText implements Function {
 
     @Override
     public Object call(Properties bindings, Object[] args) {
-        if (args.length >= 1) {
+        if (args.length == 1) {
             Object o1 = args[0];
             if (o1 != null && o1 instanceof Element) {
                 Element e1 = (Element)o1;
@@ -57,7 +57,7 @@ public class XmlText implements Function {
                 return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " failed as the first parameter is not an XML or HTML Element.  Please first use parseXml() or parseHtml() and select(query) prior to using this function");
             }
         }
-        return null;
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects a single XML or HTML element as an argument");
     }