获取表单标签中的查询字符串值

我想在asp.net的表单标签中检索查询字符串值，因为我使用了Paypal代码，在其中重定向并从页面的正文部分标签中进行检查.

i want to retrive the query string value in form tag of asp.net because i used the paypal code in which it redirect and check from the body part tag from the page.

<form method="post" action= "https://www.paypal.com/cgi-bin/webscr">
    <input type="hidden" name="cmd" value="_xclick">
    <input type="hidden" name="business" value="my@email.com">
    <input type="hidden" name="item_name" value="Item name">
    <input type="hidden" name="item_number" value="1234"> // use query string here to get value from the other page
    <input type="submit" value="Buy Now">
</form>

所以我想在值字段中使用查询字符串，其中查询字符串是来自其他页面的值.
请帮忙..
Mitesh

so i want to use query string in value field in which query string is value from the come from the other page.
please help..
Mitesh