IE和firefox通用的复制到剪贴板的JS函数

1.function copyToClipboard(txt) {  
2.     if(window.clipboardData) {  
3.             window.clipboardData.clearData();  
4.             window.clipboardData.setData("Text", txt);  
5.     } else if(navigator.userAgent.indexOf("Opera") != -1) {  
6.          window.location = txt;  
7.     } else if (window.netscape) {  
8.          try {  
9.               netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");  
10.          } catch (e) {  
11.               alert("被浏览器拒绝！\n请在浏览器地址栏输入'about:config'并回车\n然后将'signed.applets.codebase_principal_support'设置为'true'");  
12.          }  
13.          var clip = Components.classes['@mozilla.org/widget/clipboard;1'].createInstance(Components.interfaces.nsIClipboard);  
14.          if (!clip)  
15.               return;  
16.          var trans = Components.classes['@mozilla.org/widget/transferable;1'].createInstance(Components.interfaces.nsITransferable);  
17.          if (!trans)  
18.               return;  
19.          trans.addDataFlavor('text/unicode');  
20.          var str = new Object();  
21.          var len = new Object();  
22.          var str = Components.classes["@mozilla.org/supports-string;1"].createInstance(Components.interfaces.nsISupportsString);  
23.          var copytext = txt;  
24.          str.data = copytext;  
25.          trans.setTransferData("text/unicode",str,copytext.length*2);  
26.          var clipid = Components.interfaces.nsIClipboard;  
27.          if (!clip)  
28.               return false;  
29.          clip.setData(trans,null,clipid.kGlobalClipboard);  
30.          alert("复制成功！")  
31.     }  
32.}