diff --git a/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/MainFunctionNotFoundException.java b/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/MainFunctionNotFoundException.java
new file mode 100644
index 00000000000..fdbe4e5f640
--- /dev/null
+++ b/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/MainFunctionNotFoundException.java
@@ -0,0 +1,28 @@
+/*
+ * Copyright 2010-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.k2js.facade.exceptions;
+
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * @author Pavel Talanov
+ */
+public class MainFunctionNotFoundException extends TranslationException {
+    public MainFunctionNotFoundException(@NotNull String message) {
+        super(message);
+    }
+}
diff --git a/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/TranslationException.java b/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/TranslationException.java
index 54483d8f5ec..82cf86b4911 100644
--- a/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/TranslationException.java
+++ b/js/js.translator/src/org/jetbrains/k2js/facade/exceptions/TranslationException.java
@@ -23,6 +23,10 @@ import org.jetbrains.annotations.NotNull;
  */
 public class TranslationException extends Exception {
 
+    public TranslationException(@NotNull String message) {
+        super(message);
+    }
+
     public TranslationException(@NotNull Throwable cause) {
         super(cause);
     }
diff --git a/js/js.translator/src/org/jetbrains/k2js/translate/general/Translation.java b/js/js.translator/src/org/jetbrains/k2js/translate/general/Translation.java
index 94595f723c8..a73256bc3bc 100644
--- a/js/js.translator/src/org/jetbrains/k2js/translate/general/Translation.java
+++ b/js/js.translator/src/org/jetbrains/k2js/translate/general/Translation.java
@@ -26,6 +26,7 @@ import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.types.lang.JetStandardLibrary;
 import org.jetbrains.k2js.facade.MainCallParameters;
+import org.jetbrains.k2js.facade.exceptions.MainFunctionNotFoundException;
 import org.jetbrains.k2js.facade.exceptions.TranslationInternalException;
 import org.jetbrains.k2js.facade.exceptions.TranslationException;
 import org.jetbrains.k2js.facade.exceptions.UnsupportedFeatureException;
@@ -155,7 +156,7 @@ public final class Translation {
 
     @NotNull
     private static JsProgram doGenerateAst(@NotNull BindingContext bindingContext, @NotNull List<JetFile> files,
-            @NotNull MainCallParameters mainCallParameters) {
+            @NotNull MainCallParameters mainCallParameters) throws MainFunctionNotFoundException {
         //TODO: move some of the code somewhere
         JetStandardLibrary standardLibrary = JetStandardLibrary.getInstance();
         StaticContext staticContext = StaticContext.generateStaticContext(standardLibrary, bindingContext);
@@ -172,10 +173,11 @@ public final class Translation {
 
     @NotNull
     private static JsStatement generateCallToMain(@NotNull TranslationContext context, @NotNull List<JetFile> files,
-            @NotNull List<String> arguments) {
+            @NotNull List<String> arguments) throws MainFunctionNotFoundException {
         JetNamedFunction mainFunction = getMainFunction(files);
-        //TODO: throw correct exception
-        assert mainFunction != null;
+        if (mainFunction == null) {
+            throw new MainFunctionNotFoundException("Main function was not found. Please check compiler arguments");
+        }
         JsInvocation translatedCall = generateInvocation(context, mainFunction);
         setArguments(context, arguments, translatedCall);
         return translatedCall.makeStmt();