js设置文本框中焦点位置在最后的示例代码(简单实用)

var tar=document.getElementByIdx_x("name");
if(tar.attachEvent){
tar.attachEvent('onmouseover',focus(tar),false);
}else{
tar.addEventListener('mouseover',focus(tar),false);
}
function focus(tar){

    tar.focus();
    tar.value=tar.value;
}