/*
Created on 2009.9.4-bym
*/
function $Elem(el){return typeof el == 'string' ?  document.getElementById(el) : el;};
function inputTrim(inp,clear){
inp = $Elem(inp);
var val  = (inp.value||'').replace(/^\s+|\s+$/,'');
if(clear) inp.value = val;
return val;
}
var $E = function addEvent(el,name,fn){
el = $Elem(el);if(!el) return;
if(el.addEventListener) {
el.addEventListener(name,fn,false);
}else{
el.attachEvent('on'+name,fn);
}
return this;
}
function addEvents(elArr){
for(var i = 0, l = elArr.length, el = elArr[i]; i < l; i++){
addEvent(el.el,el.name,el.fn);
}
}
function setDisplay(el,display){
if(!el) return;
el.style.display = display || 'inline';
}
function addClass(el, cls){
if(el.className.indexOf(cls) == -1){
el.className += ' ' + cls;
}
}
function removeClass(el,cls){
el.className = el.className.replace(new RegExp('(^|\\s)' + cls + '(?:\\s|$)'), '$1');
}
//bind placeholder for input
function placeHolderBind(inputid,labelid){
setTimeout(function(){
//if document focus on this element,do not show label tips
if(inputid.className.indexOf('focused') == -1){
setDisplay(labelid,inputTrim(inputid,true) ? 'none' : 'inline');
}
},500);
$E(inputid,'blur',function(){
removeClass(inputid,'focused');
!inputTrim(inputid,true) && setDisplay(labelid,'inline');
}).$E(inputid,'focus',function(){
addClass(inputid,'focused');
setDisplay(labelid,'none');
}).$E(inputid,'keydown',function(){
setDisplay(labelid,'none');
});
//初始化时如果输入框有内容，则不显示label 
!inputTrim(inputid,true) && setDisplay(labelid,'inline');
}
window.onload = function(){
var login = $Elem('loginid'),label = $Elem('loginlabel'),pwd = $Elem('pwdid'),submit = $Elem('submitbtn'),verifycode = $Elem('verifycode');
if(!login || !pwd || !submit) return;
placeHolderBind(login,label);
//给密码框添加焦点事件 
$E(pwd,'blur',function(){
removeClass(pwd,'focused');
}).$E(pwd,'focus',function(){
addClass(pwd,'focused');
});
//给提交按钮添加悬停事件 
$E(submit,'mouseover',function(){
addClass(submit,'over');
}).$E(submit,'mouseout',function(){
removeClass(submit,'over');
});
//有可能会有验证码出现的情况，如主登录页面超过一定的次数时 
if(verifycode){
$E(verifycode,'blur',function(){
removeClass(verifycode,'focused');
}).$E(verifycode,'focus',function(){
addClass(verifycode,'focused');
});
}
//攻取焦点 
if(login.value == ''){
setTimeout(function(){login.focus();},200);
}else if(pwd.value == ''){
setTimeout(function(){pwd.focus();},200);
}else if(verifycode && verifycode.value == ''){
setTimeout(function(){verifycode.focus();},200);
}
}