<select mo:type="ComboBox" mo:name="${fieldName}" mo:value="${value}"  
       mo:props="nonBlank:${nonBlank}, valHandler:${valHandler}, valErrorHandler:${valErrorHandler}">
    <xsl:for-each select="/root/${dataRequestName}/item">
      <option value="{${optionValueNode}}"><xsl:value-of select="${optionTextNode}"/></option>
    </xsl:for-each>  
  </select>

${fieldName}

The name of the ProcessField

${initialValue}

The initial value of the field

${nonBlank}

If "true" then the field cannot be left blank

${valHandler}

The name of the validation handler function

${valErrorHandler}

The name of the validation error handler function.

${dataRequestName}

The name of the data request. There must be an identically named dataRequest definition in the configuration.

${optionValueNode}

The name of the XML Node for option text that exists as a sub-node under
"/root/${dataRequestName}/item"

${optionTextNode}

The name of the XML Node for option value that exists as a sub-node under
"/root/${dataRequestName}/item"