jquery禁止回车触发表单提交

<form class="form-inline definewidth m20" action="/" method="get"> 
            <input type="text" name="title" id="title"class="abc" value="">   
            <button type="submit" class="btn" style="margin-right:20px">查询</button>
            <select name="school_type" id="school_type">
</form>
<td style="width:90px; height:24px; text-align:center"><input   type="text" name="test" value="" class="a"></td>

$('.a').keypress(function(e){
            if(e.keyCode==13){
                e.preventDefault();
            }