asp.net url重写

自己写正则
<RewriterConfig>
          <Rules>
<RewriterRule>
    <LookFor>~/(\d{1,})\.html </LookFor>
    <SendTo>~/product.asp?id=$1 </SendTo>
</RewriterRule>
<RewriterRule>
    <LookFor>~/(\d{1,})/(\w+$)\.html </LookFor>
    <SendTo>~/product.asp?id=$1&amp;keyword=$2 </SendTo>
</RewriterRule>
<RewriterRule>
    <LookFor>~/(\d{1,})/(\w+$)/(\w+$)\.html </LookFor>
    <SendTo>~/product.asp?id=$1&amp;keyword=$2&amp;find=$3 </SendTo>
</RewriterRule>
</Rules>
     </RewriterConfig>
规则还是自己定，会写正则表达式就行，然后链接的URL参照定义的规则写