title: I can't update software using yum on CentOS
body: <p>When I use the command <code>yum update</code> to update the software on CentOS, it gives the following error and not sure how to fix it:</p>
  
  <pre><code> Error: Missing Dependency: php-common = 5.2.4-el5.centos is needed by package php-mhash
   Error: Missing Dependency: libnss3.so(NSS_3.12) is needed by package libcurl
   Error: Missing Dependency: libnssutil3.so is needed by package libcurl
  </code></pre>
  
  <p>Any suggestion?</p>