<cfsearch> for mutiple fields

How can search for mutiple fields (criterias)? my code below returns nothing?

Form.cfm:

<form action="search.cfm" method="post">

Name:<input type="text" name="name" />

Desc:<input type="text" name="desc" />

<input type="submit" name="submit" value="Search" />

</form>

search.cfm

<cfset searchTerm = "#form.name#,#form.desc#">

<cfsearch name="searchResults" collection="mycollection" criteria="#searchTerm#">

  <cfdump var="#searchResults#">

thanks