Can't solve problem with AccessControlException:access denied

Question

i am trying to develop an applet. a button is place to open file from the local system. before i have done this, the applet work perfectly fine, and after i have written a class for file reader and some methods in the applet class, it doesn't function probably. when the applet is being loaded, an error message say java.security.AccessControlException:access denied. i am not sure whether it is because i have tried to pass the class itself into other class as mark with **** below.
many thanks for your help.
tim
============================================
public class TSP extends Applet implements ActionListener, MouseListener{
public void actionPerformed(ActionEvent e){
if(e.getSource() == inputFile && openFile()){
//do whatever i want
public boolean openFile() {
//open the file chooser
int returnVal = fChooser.showOpenDialog(TSP.this);
if (returnVal == JFileChooser.APPROVE_OPTION) {
tspSF = fChooser.getSelectedFile();
System.out.println(tspSF.getName()+" is chosen");
**** inputFile = new Input(this, errHandler);
inputFile.readandinputdata(tspSF);
return true;
else return false;
public init(){......}
==========================================
public class Input{
public Input(TSP tsp, ErrHandler errHandler){
**** this.tsp = tsp;
this.errHandler = errHandler;
// method readandinputdata
public void readandinputdata(File tspSF){
try {
input = new BufferedReader(new FileReader(tspSF));
catch....
try {
//read in the first line
data = input.readLine();
while (data != null){
st = new StringTokenizer(data);
nodeNumber = tokenChanger.parseInt(st.nextToken());
     x = tokenChanger.parseInt(st.nextToken());
     y = tokenChanger.parseInt(st.nextToken());
     //store the x and y with some method in TSP class
**** tsp.storeNodes(x, y);
     // read next time                    
     data = input.readLine();     
}// end of while data != null
closeFile();
} // end of second scan
catch.....
}//end of readandinoputdata
}

Answer 1

Go to the MSDOS command prompt.
Type in policytool.exe.
This will bring up the .java.policy file.
If not recognized do a search for policytool.exe.
Backup your .java.policy file first.
Edit the .java.policy file or credit a new one for your application.
Codebase: "http://65.33.143.92/mydirectory/" which is
C:\Inetpub\wwwroot\mydirectory or
Codebase: file:///inetpub/wwwroot/mydirectory.
I'm not sure about the Windows syntax.
Add the permissions that you need.
Then save the file.