JS 复制表单内容到剪切板

<script language="javascript">
            function CopyIt(theField)
            {
                var tempval=document.getElementById(theField)
                tempval.focus()
                tempval.select()
                copyToClipboard(tempval.value);
                //therange=tempval.createTextRange()

                //therange.execCommand("Copy")

                //window.clipboardData.setData("text",tempval.value);

            }
            function copyToClipboard(txt) {
                  if(window.clipboardData) {
                          window.clipboardData.clearData();
                          window.clipboardData.setData("Text", txt);
                        alert("复制成功");
                  } else if(navigator.userAgent.indexOf("Opera") != -1) {
                       window.location = txt;
                  } else if (window.netscape) {
                       try {
                            netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
                       } catch (e) {
                            alert("如果您正在使用FireFox！\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'");
                       }
                       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)
                            return false;
                       clip.setData(trans,null,clipid.kGlobalClipboard);
                       alert("复制成功！")
                  }
            }
            </script>