<form action="{pboot:scaction}"  method="get">

                    <input type="text" name="keyword" class="s-input" placeholder="请输入产品关键字">

                    <input type="hidden" name="field" value="title" >

                	  <input type="hidden" name="field" value="author" >

               	  <input type="hidden" name="field" value="content" >

                    <button class="s-btn"><span class="fa fa-search"></span></button>

                </form>