设置焦点放到最后

<script language="javascript">
function getSelectPos(obj){
    var esrc = document.getElementById(obj);
    if(esrc==null){
       esrc=event.srcElement;
    }
    var rtextRange =esrc.createTextRange();
    rtextRange.moveStart('character',esrc.value.length);
    rtextRange.collapse(true);
    rtextRange.select();
}
</script>