Help for installation of xpcom components

Hello,
         I am trying to install an XPCOM component in the mozilla client in the components directory.
         I am able to place the XPCOM components in the components directory. Hence if I access the component just after installation it gives the error  "Type Error Components.classes[cid] has no properties " my install.js file is as below.

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var err = initInstall("WSInstall","SamTest",1.0);
if(err != SUCCESS)
    alert("Initialised");

var chromeDir = getFolder("chrome");
var compDir = getFolder("components");

err = addFile("SamTest.dll",1.0, "SamTest.dll",compDir,"",1);
if (err != SUCCESS)
 alert("SamTest.dll could not be downloaded in Components dir");

err = addFile("ISamTest.xpt",1.0, "ISamTest.xpt",compDir,"",1);
if (err != SUCCESS)
 alert("ISamTest.xpt could not be downloaded in Components dir");


err = addFile("wsinstall.jar",1.0, "wsinstall.jar",chromeDir,"");
if (err != SUCCESS)
 alert("wsinstall.jar could not be downloaded in Components dir");

err = registerChrome(CONTENT,getFolder(chromeDir,"wsinstall.jar"),"content/wsinstall/");
if (err != SUCCESS)
 alert("register chrome failed");

if (err==SUCCESS)
{
 err = performInstall();
 alert ("performInstall() returned: " + err);
  logComment("performInstall() returned: " + err);
}
else
 cancelInstall(err);
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 I want to register SamTest.dll .

With Regards,
Ajit