Java java server pages and netbeans

I have developed a .jsp website using NetBeans. It is working perfectly well when I run it from NetBeans but when I clean and build the project and copy the .war file from the dist folder and copy in the webapps folder of the TomCat 5.0 that is installed alongwith no .jsp file is being executed.

The error shows:

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:414)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:472)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:451)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
        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:106)
        org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:935)
        org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:764)
        org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:382)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:472)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:451)
        org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
        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)

Sometimes while cleaning and building the project an error occurs in NetBeans that MySQL driver.jar i.e. included library cannot be deleted.