$("form > input">) 可以匹配表单下所有的子级input元素
node2:/var/www/html#cat m19.html
<script src="jquery-1.6.4.js" type="text/javascript"></script>
<html>
<form>
<div id="aaaa" class="red">测试1</div>
<input value="按钮1">
<div id="bbbb" class="blue">测试2</div>
<a><input value="按钮2"></a>
<div id="cccc" clas="orange">测试3</div>
<span class="red">SPAN</span>
</form>
<input value="按钮">
</html>
<script>
$(function(){
$("form > input").css("color","red")
})
</script>