processmaker-files/workflow/engine/xmlform/outputdocs/outputdocsUploadFile.xml

<?xml version="1.0" encoding="UTF-8"?>
<dynaForm target="xx" width="450px">
  <OUT_DOC_UID type="hidden"/>
  <FILENAME type="phpVariable"/>
  <FILELINK type="phpVariable"/>
  <TITLE1 type="title">
    <en><![CDATA[Download]]></en>
  </TITLE1>
  <OUT_DOC_LINK type="link" value="@#FILENAME" link="@#FILELINK" target="_blank">
    <en><![CDATA[Click in the link to download current file]]></en>
  </OUT_DOC_LINK>
  <TITLE2 type="title">
    <en><![CDATA[Upload]]></en>
  </TITLE2>
  <OUT_DOC_FILE type="file">
    <en><![CDATA[Upload a modified file]]></en>
  </OUT_DOC_FILE>
  <BTN type="submit" onclick="submitIframe( this ); ">
    <en><![CDATA[upload]]></en>
  </BTN>
  <javasc type="javascript"><![CDATA[
  function submitIframe ( th ) {
    th.form.target = 'uploadFormIframe';
    th.submit();    
  }
]]></javasc>
</dynaForm>