javascript 复制到粘贴板

<script type="text/javascript">
<!--
function clip(text){
str=eval("document." + text)
str.select()
str = document.selection.createRange();
clipboardData.setData('text',(str.text));
}
//-->
</script>
<form name="form">
<a href="java script:clip('form.copy')">
复制到剪贴板</a><br>
<textarea rows="16" cols="40" name="copy"></textarea>
</form>