function _setViewer(welTarget){
        var sMarkdownText = welTarget.text();
        var sContentBody  = (sMarkdownText) ? _renderMarkdown(sMarkdownText) : welTarget.html();
        $('.markdown-loader').remove();
        welTarget.html(sContentBody).removeClass('markdown-before');
    }
set Markdown Viewer

@param {Wrapped Element} welTarget is not <textarea> or <input>