---
title: Screen.availTop
slug: Web/API/Screen/availTop
translation_of: Web/API/Screen/availTop
---
<p>{{ ApiRef() }}</p>
<h3 id="Summary" name="Summary">概述</h3>
<p>浏览器窗口在屏幕上的可占用空间上边距离屏幕上边界的像素值。</p>
<h3 id="Syntax" name="Syntax">语法</h3>
<pre class="eval">iAvail = window.screen.availTop
</pre>
<h3 id="Example" name="Example">示例</h3>
<pre class="eval">setY = window.screen.height - window.screen.availTop;
setX = window.screen.width - window.screen.availLeft;
window.moveTo(setX, setY);
</pre>
<h3 id="Notes" name="Notes">备注</h3>
<p>大多数情况下，该属性返回 0。</p>
<h3 id="Specification" name="Specification">规范</h3>
<p>DOM Level 0。不属于任何规范。</p>
<div class="noinclude">
  </div>
<p>{{ languages( { "ja": "ja/DOM/window.screen.availTop" } ) }}</p>