怎么样从表单中删除一个控件?

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<title>WebForm1</title>
<meta name="GENERATOR" content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" content="Visual Basic .NET 7.1">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
<script language="javascript">
function hideDropDownList() {
document.getElementById("select1").style.visibility  = "hidden";
}

function clearDropDownList() {
var obj = document.getElementById("select1");
obj.outerHTML = "";

}
</script>
</HEAD>
<body MS_POSITIONING="GridLayout">
<FONT face="宋体">
<SELECT id="select1" style="Z-INDEX: 101; LEFT: 296px; WIDTH: 232px; POSITION: absolute; TOP: 88px; HEIGHT: 56px">
<OPTION>adasd</OPTION>
<OPTION>1</OPTION>
<OPTION>2</OPTION>
<OPTION selected>3</OPTION>
</SELECT></FONT> <INPUT style="Z-INDEX: 102; LEFT: 216px; WIDTH: 64px; POSITION: absolute; TOP: 200px; HEIGHT: 32px"
type="button" value="隐藏" onclick="hideDropDownList()"><INPUT style="Z-INDEX: 103; LEFT: 360px; WIDTH: 96px; POSITION: absolute; TOP: 200px; HEIGHT: 32px"
type="button" value="清除" onclick="clearDropDownList()">
</body>
</HTML>