title: How to link to form select option dropdowns
body: <p>I have a webpage using 4 search box's in 2 in header &amp; 2 in the body of homepage.
  Both Header form &amp; form in body of homepage are the same and query the same search page.</p>
  
  <p>My Question is how could I link dropdowns so that when one changes the others follow.</p>
  
  <p>At the moment I am using php to switch to appropriate categories on arrival to page(s).<br>
  eg:
  <code>&lt;option value='-1' &lt;?php if ($cat == "-1")  {print("selected");}?&gt;&gt;All Categories&lt;/option&gt;
  &lt;option value='0'&lt;?php if ($cat == "0")  {print("selected");}?&gt;&gt;Category One&lt;/option&gt;
  &lt;option value='1' &lt;?php if ($cat == "1")  {print("selected");}?&gt;&gt;Category Two&lt;/option&gt;</code></p>
  
  <p>Which works great when arriving on page(s) after query.</p>
  
  <p>However Because there are 4 forms on my home page I was hoping to somehow dynamically when user changes one of the &lt; select >&lt; options > on page then the other &lt; select >&lt; options > in header and other places all change to same value also?</p>
  
  <p>Any ideas?</p>