I face system error when I try to run my program.....
Below is my code....

myProgramappui.cpp
------------------------------

const TPtrC KTestFile=_L("C:\\System\\apps\\testdata\\testdata.dat");
const TUint8* KTestData=_S8("12345\n");
const TInt KTestLength=5;
const TPtrC8 KTestDes(KTestData,KTestLength);


void CTestdataAppUi::HandleCommandL(TInt aCommand)
   {
   switch ( aCommand )
       {
       case EAknSoftkeyBack:
       case EEikCmdExit:
           {
           Exit();
           break;
           }
       case EtestdataCmdAppTest:
           {
           Write();
           break;
           }
       default:
           break;      
       }
   }

void CTestdataAppUi::Write()
{
TBuf8<KTestLength+1> buf;
RFs TheFs;
RFile file;      

User::LeaveIfError(TheFs.Connect());
User::LeaveIfError(file.Open(TheFs,KTestFile,EFileWrite));  
RFile f=file;
RFileWriteStream out(f);
out.WriteL(KTestDes);
out.CommitL();

TInt iFileSize;
file.Size(iFileSize);
out.Attach(file, iFileSize);
out.WriteL(KTestDes);
out.Close();
TheFs.Close();
}

myprogramcontainer.cpp
----------------------------------

const TPtrC KTestFile=_L("C:\\System\\apps\\testdata\\testdata.dat");

void CTestdataContainer::ConstructL(const TRect& aRect)
{
CreateWindowL();
   
RFs TheFs;
RFile file;
TBuf8<50> buf;

User::LeaveIfError(TheFs.Connect());
User::LeaveIfError(file.Open(TheFs,KTestFile,EFileRead));
RFile f=file;
RFileReadStream in(f);
in.ReadL(buf);
in.Close();
TheFs.Close();

HBufC* buf16 = HBufC::NewLC(buf.Length());   
buf16->Des().Copy(buf);

   
iLabel = new (ELeave) CEikLabel;
iLabel->SetContainerWindowL( *this );
iLabel->SetTextL(* buf16);
   
CleanupStack::PopAndDestroy(buf16);

SetRect(aRect);
ActivateL();
}

any one know how to solve this problem?

I know there are no global variable in symbian...but anyone know how to reference variables and contansts for different classes....like I want to reference variables and contansts  in appui from container class....

million thanks in advance.....