title: How to search html file for simple string?
body: <p><a href="http://www.amazon.com/gp/offer-listing/B00519RW1U/" rel="nofollow noreferrer">Consider this link from Amazon.</a>  </p>
  
  <p>If you notice, each seller has this block (similar, at least):</p>
  
  <pre><code>&lt;a href="http://www.amazon.com/shops/AN8LN2YPKS7DF/ref=olp_merch_name_2"&gt;
  &lt;img src="http://ecx.images-amazon.com/images/I/41UQmT7-XyL.jpg" width="120" alt="DataVision Computer Video" height="30" border="0" /&gt;
  &lt;/a&gt; //and other junk
  </code></pre>
  
  <p>I want to search this page for <code>http://ecx.images-amazon.com/images/I/41UQmT7-XyL.jpg</code>, which is the seller image (which I already have the link for).  I just want to know if the search produced results, or not.  I don't even need to know more than that.  Is this possible?  How can I do it using PHP?</p>