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HTML is good for debugging, but probably is not suitable for your application.
See complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query>
    <allusers>
      <u name="Y0360zmae" userid="842952" />
      <u name="Y0516bxrn" userid="843806" />
      <u name="Y06vdmb95" userid="847629" />
      <u name="Y0a9FBSyfr" userid="765765" />
      <u name="Y0q0ie2d3" userid="1030328" />
      <u name="Y0qyxij3" userid="408246" />
      <u name="Y0s83ki1e1p" userid="665602" />
      <u name="Y0t6iz4h8" userid="992273" />
      <u name="Y0w7jm6a8" userid="1015303" />
      <u name="Y0wyx0" userid="230984" />
    </allusers>
  </query>
  <query-continue>
    <allusers aufrom="Y0xoo3n886" />
  </query-continue>
</api>