通过javascript获取所有的表单值

I have form:

我有形式:

<form onchange="allvaluestostring()">       
    <select name="status">
         <option value="*">All</option>
         <option value="1">Active</option>
         <option value="0">Inactive</option>
    </select>
    <select name="size">
          <option value="*">All</option>
          <option value="small">Small</option>
          <option value="big">Big</option>
    </select>
</form>
<form onchange="allvalue