适应性超强的focus
//功能: 能用于GrayBox弹出后, 页面加载完成时置焦点 function setFocus(obj) { if (obj.setSelectionRange) { setTimeout(function () { obj.setSelectionRange(0, 0); obj.focus(); }, 100); } else { if (obj.createTextRange) { var range = obj.createTextRange(); range.collapse(true); range.moveEnd("character", 0); range.moveStart("character", 0); range.select(); } try { setTimeout(function () { obj.focus(); }, 100); } catch (e) { } } }