Error message while using trial version.

Compiling code. 0.03
Generating R file. 0.00
Compiling generated Java code. Error
javac 1.5.0_22
src\anywheresoftware\b4a\hellow\main.java:3: cannot access anywheresoftware.b4a.B4AMenuItem
bad class file: C:\Program Files\Anywhere Software\Basic4android\libraries\B4AShared.jar(anywheresoftware/b4a/B4AMenuItem.class)
class file has wrong version 50.0, should be 49.0
Please remove or make sure it appears in the correct subdirectory of the classpath.
import anywheresoftware.b4a.B4AMenuItem;
^
1 error

Is this message comes up because i use a trial version.

You should install Java 6 JDK. You are currently using Java 5.

There is a link to the correct version here: Basic4android (Basic for Android) - Android programming with Gui designer