jq的next()函数时，为什么显示thisObj.next is not a function？

-----HTML----
<img class="my-img" id="myimg" src="images/resources.png" onmouseout="hidebutton(this)"
onmouseover="showbutton(this)">
<div id="button" class="button">
<button>隐藏按钮</button>
</div>
----------jq--------
function hidebutton(thisObj) {
debugger;
thisObj.next(".button").css("display", "none");
}