我有一个带数据的字符串，我想把这个字符串文件存储到xml中。我应该做什么?

i have a string which contain..

我有一根弦。

<response type="1">
<terminal_id>1000099999</terminal_id>
<merchant_id>10004444</merchant_id>
<merchant_info>Mc Donald's - Abdoun</merchant_info>
<transaction_id>7777771</transaction_id>
<process_status>1</process_status>
<process_status_desc>Success</process_status_desc>
<process_date>30/06/2011 12:39:32</process_date>
<menu_version_id>1</menu_version_id>
<menu>
<menu type="campaigns">
<menu campaign_id="1" title_en="2nd sandwich free" title_ar="??????? ????? ??????">
<menu>
</menu>
<specific_inputs>
<input_item key="amount" type="float" title_en="Amount" title_ar="??????"/>
</specific_inputs>
</menu>
</menu>
<menu type="fixed_text" id="1" title_en="Help" title_ar="??????">
<text_en>When making sales, first the campaign should be selected. Then the </text_en>
<text_ar>When making sales, first the
</text_ar>
</menu>
<menu type="fixed_text" id="2" title_en="Support" title_ar="???">
<text_en>Mobilera: 06-583 3500 or 06-583 3400</text_en>

<text_ar>Mobilera: 06-583 3500 or 06-583 3400</text_ar>
</menu>
</menu>
</response>

<response type="1">
<terminal_id>1000099999</terminal_id>
<merchant_id>10004444</merchant_id>
<merchant_info>Mc Donald's - Abdoun</merchant_info>
<transaction_id>7777771</transaction_id>
<process_status>1</process_status>
<process_status_desc>Success</process_status_desc>
<process_date>30/06/2011 12:39:32</process_date>
<menu_version_id>1</menu_version_id>
<menu>

<menu type="campaigns">
<menu campaign_id="1" title_en="2nd sandwich free" title_ar="??????? ????? ??????">
<menu>
</menu>
<specific_inputs>
<input_item key="amount" type="float" title_en="Amount" title_ar="??????"/>
</specific_inputs>
</menu>
</menu>
<menu type="fixed_text" id="1" title_en="Help" title_ar="??????">
<text_en>When making sales, first the campaign should be selected. Then the </text_en>
<text_ar>When making sales, first the
</text_ar>
</menu>
<menu type="fixed_text" id="2" title_en="Support" title_ar="???">
<text_en>Mobilera: 06-583 3500 or 06-583 3400</text_en>

<text_ar>Mobilera: 06-583 3500 or 06-583 3400</text_ar>
</menu>
</menu>
</response>
<res