Replacing " (double quote) with ' (single quote)

Question

Hi there,
I have the following method to manipulate user input. All I want to do is, to replace the double quote with a single quote. The implementation I tried was,
this.replace(desc, "\"", "'");
This does not work for me. It jsut removes the double quote and does not introduces the single quote. Could any one please advise?
Thanks,
Des
public static String replace(String line, String oldString, String newString) {
          if(line != null && oldString != null && newString != null) {
               int index = 0;
               while ((index = line.indexOf(oldString, index)) >= 0) {
                    line = line.substring(0, index) +
                         newString +
                         line.substring(index + oldString.length());
                    index += newString.length();
          return line;
     }

Answer 1

Bad luck.. I am unable to get it still.
This is the code I am using (implemetation is in a JSP. I am using this code to test it).
public class Test{
public static void main(String args[]){
     String s = args[0];
     Test t = new Test();
     String doubleQuote = "\"";
     System.out.println(" output :"+ t.replace(s,doubleQuote,"'"));
     //System.out.println(" output :"+ t.replace(s,"\"","'"));
     //System.out.println(" output :"+ t.replace('"', '\''));
public static String replace(String line, String oldString, String newString) {
          if(line != null && oldString != null && newString != null) {
               int index = 0;
               while ((index = line.indexOf(oldString, index)) >= 0) {
                         System.out.println(" line count :");
                    line = line.substring(0, index) +
                         newString +
                         line.substring(index + oldString.length());
                    index += newString.length();
          return line;
}mshn02
The main problem is I am stuck with the server's version of Java (which I have no control on it). I could not use 1.4.2