function CopyById(id) {
if (!document.body.createControlRange){
return; //只支持IE哦
}
var ctrl = document.body.createControlRange();
var domid=document.getElementById(id);
domid.contentEditable = true;
ctrl.addElement(domid);
ctrl.execCommand('Copy');
domid.contentEditable = false;
alert('复制完成');
}