支持ie与FireFox的剪切板操作代码

function getClipboard()
{
if (window.clipboardData)
{
return (window.clipboardData.getData('text'));
}
else
{
if (window.netscape)
{
try
{
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
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");
clip.getData(trans, clip.kGlobalClipboard);
var str = new Object();
var len = new Object();
trans.getTransferData("text/unicode", str, len);
}
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，相对路径为firefox根目录/greprefs/all.js");
return null;
}
if (str)
{
if (Components.interfaces.nsISupportsWString)
{
str = str.value.QueryInterface(Components.interfaces.nsISupportsWString);
}
else
{
if (Components.interfaces.nsISupportsString)
{
str = str.value.QueryInterface(Components.interfaces.nsISupportsString);
}
else
{
str = null;
}
}
}
if (str)
{
return (str.data.substring(0, len.value / 2));
}
}
}
return null;
}

copy2Clipboard=function(txt){
    if(window.clipboardData){
window.clipboardData.clearData();
        window.clipboardData.setData("Text",txt);
    }
    else if(navigator.userAgent.indexOf("Opera")!=-1){
        window.location=txt;
    }
    else if(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，相对路径为firefox根目录/greprefs/all.js");
            return false;
        }
        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);
    }
}