js实现运行、全选、复制、保存代码程序

<input type="button" name="Submit" value="运行代码" onclick="runCode('content')"/>
<input type="button" name="Submit3" value="全选代码" onclick="$('content').select();" />
<input type="button" name="Submit4" value="复制代码" onclick="oCopy('content')" />
<input type="button" name="Submit2" value="保存代码" onclick="saveCode('content')" />

Array.prototype.push = function(value) {
 this[this.length] = value;
 return this.length;
}
function $(objname){return document.getElementById(objname);}
function runCode(objname) {
        var winname = window.open('', "_blank", '');
 var obj = $(objname);
        winname.document.open('text/html', 'replace');
 winname.opener = null // 防止代码对论谈页面修改
        winname.document.write(obj.value);
        winname.document.close();
}
function saveCode(objname){
        var winname = window.open('', '_blank', 'top=10000');
        winname.document.open('text/html', 'replace');
 var obj = $(objname);
        winname.document.write(obj.value);
        winname.document.execCommand('saveas','','code.htm');
        winname.close();
}

function oCopy(objname){
       var obj = $(objname);
       obj.select();
       js=obj.createTextRange();
       js.execCommand("Copy");
       alert("www.111cn.net提示：代码已经被成功复制！");
}

</script>