div失去焦点事件（简述js中获取焦点事件）
例 1.1 onblur和onfocus
马克-to-win：onblur失去焦点和onfocus得到焦点事件。
&<!DOCTYPE HTML PUBLIC &“-//W3C//DTD HTML 4.0 Transitional//EN&”&>
&<HTML&>
&<head&>
&<meta http-equiv=&”content-type&” content=&”text/html; charset=utf-8&″/&>
&<SCRIPT LANGUAGE=&”JavaScript&”&>
&<!&–
function check(a)
{
var username = a.value;
if (username == &“&”)
{
/*String.fontcolor() (Method)
Encapsulates the string within an &<FONT COLOR=&”&…&”&> tag context.*/
document.getElementById(&“error&”).innerHTML = &“用户名不能为空！&”.fontcolor(&“red&”);
}
}
function rese()
{
document.getElementById(&“error&”).innerHTML = &“&”;
}
//&–&>
&</SCRIPT&>
&</HEAD&>
&<BODY onload=&”document.getElementById(&‘u&’).focus()&”&>