非原创，来源网络。感谢原作者奉献如此精彩文章。 http://www.cnblogs.com/JustinYoung/articles/1018752.html
<!doctype html public "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"/><meta name="Keywords" content="YES!B/S!"/><meta name="Description" content="This page is from http://Justinyoung.cnblogs.com"/><title>CSS/Javascript demo</title><script type="text/javascript" language="javascript">
function test(){
copyToClipboard("dddd");
} copyToClipboard =function(txt) {
if(window.clipboardData) {
window.clipboardData.clearData(); window.clipboardData.setData("Text", txt);}elseif(navigator.userAgent.indexOf("Opera") !=-1) {window.location = txt;}elseif (window.netscape) {try{netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");}catch (e) {alert("您的firefox安全限制限制您进行剪贴板操作，请打开’about:config’将signed.applets.codebase_principal_support’设置为true’之后重试");returnfalse;
}var clip = Components.classes['@mozilla.org/widget/clipboard;1'].createInstance(Components.interfaces.nsIClipboard);if (!clip)return;var trans = Components.classes['@mozilla.org/widget/transferable;1'].createInstance(Components.interfaces.nsITransferable);if (!trans)return;trans.addDataFlavor('text/unicode');var str =new Object();var len =new Object();var str = Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);var copytext = txt;str.data = copytext;trans.setTransferData("text/unicode",str,copytext.length*2);var clipid = Components.interfaces.nsIClipboard;if (!clip)returnfalse;clip.setData(trans,null,clipid.kGlobalClipboard);}}</script></head><body> <button onclick="test();">复制到粘贴板</button></body></html>