Unable to find a javac compiler... HELP

I previewed the web page I'm makingwith dreamweaver but this error page appeared...

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

org.apache.jasper.JasperException: Unable to compile class for JSP

org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:97)

org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:346)

org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:439)

org.apache.jasper.compiler.Compiler.compile(Compiler.java:497)

org.apache.jasper.compiler.Compiler.compile(Compiler.java:476)

org.apache.jasper.compiler.Compiler.compile(Compiler.java:464)

org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:511)

org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:295)

org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)

org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)

javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

root cause

Unable to find a javac compiler;

com.sun.tools.javac.Main is not on the classpath.

Perhaps JAVA_HOME does not point to the JDK

org.apache.tools.ant.taskdefs.compilers.CompilerAdapterFactory.getCompiler(CompilerAdapterFactory.java:105)

org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:929)

org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:758)

org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:407)