I have to develop one shopping cart app.

Here i have to add the product only 5.otherwise have to display the message on alert dialog like 5 products only allowed.

How can i develop this.please help me

This is my code:

ImageButton mImgAddCart = (ImageButton) findViewById(R.id.img_add);
    mImgAddCart.setOnClickListener(new OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub
            mTitle = txttitle.getText().toString();
            mCost = text_cost_code.getText().toString();
            mCost = mCost.replace("From ", "");
            mTotal = txt_total.getText().toString();
            mTotal = mTotal.replace("From ", "");
            mQty = edit_qty_code.getText().toString();

            if (Constants.mItem_Detail.size() <= 0) {
                HashMap<String, String> mTempObj = new HashMap<String, String>();
                mTempObj.put(KEY_TITLE, mTitle);
                mTempObj.put(KEY_QTY, mQty);
                mTempObj.put(KEY_COST, mCost);
                mTempObj.put(KEY_TOTAL, mTotal);

                Constants.mItem_Detail.add(mTempObj);

            } else {
                for (int i = 0; i < Constants.mItem_Detail.size(); i++) {
                    if (Constants.mItem_Detail.get(i).get(KEY_TITLE)
                            .equals(mTitle)) {
                        Constants.mItem_Detail.remove(i);


                        break;

                    } else {

                    }
                }

                HashMap<String, String> mTempObj = new HashMap<String, String>();
                mTempObj.put(KEY_TITLE, mTitle);
                mTempObj.put(KEY_QTY, mQty);
                mTempObj.put(KEY_COST, mCost);
                mTempObj.put(KEY_TOTAL, mTotal);

                Constants.mItem_Detail.add(mTempObj); 
            }

            AlertDialog.Builder alertdialog = new AlertDialog.Builder(
                    Small.this);
            alertdialog.setTitle(getResources()
                    .getString(R.string.app_name));
            alertdialog.setMessage("Add in ViewCart");

            alertdialog.setPositiveButton("OK",
                    new DialogInterface.OnClickListener() {

                        @Override
                        public void onClick(DialogInterface dialog,
                                int which) {
                            // TODO Auto-generated method stub
                            finish();
                        }
                    });

            alertdialog.show();

        }
    });

How can i set the condition for this.please give me one idea.