JS 按钮点击触发(兼容IE、火狐)

代码如下:
function clickButton(id) {
            if (document.all) {
                document.getElementById(id).click();
            }
            else {
                var evt = document.createEvent("MouseEvents");
                evt.initEvent("click", true, true);
                document.getElementById(id).dispatchEvent(evt);
            }
        }