placeholder兼容IE6-9代码

placeholderIE:function(){
//判断浏览器是否支持 placeholder属性
function isPlaceholder(){
var input = document.createElement('input');
return 'placeholder' in input;
}
//对不支持placeholder的浏览器处理
if(!isPlaceholder()){
$("input").not("input[type='password']").each(//把input绑定事件 排除password框
function(){
if($(this).val()=="" && $(this).attr("placeholder")!=""){
$(this).val($(this).attr("placeholder")).css('color','#999');
$(this).focus(function(){
if($(this).css('color') == 'rgb(153, 153, 153)'){
$(this).val('').css('color','#404040')
}
});
$(this).blur(function(){
if($(this).val()=="") {
$(this).val($(this).attr("placeholder")).css('color','#999');
}else{
$(this).css('color','#404040')
}
});
}
});
//对password框的特殊处理1.创建一个text框 2获取焦点和失去焦点的时候切换
var pwdField = $("input[type=password]");
var pwdVal = pwdField.attr('placeholder');
pwdField.after('<input id="pwdPlaceholder" class="input-txt" type="text" value='+pwdVal+' autocomplete="off" />');
var pwdPlaceholder = $('#pwdPlaceholder');
pwdPlaceholder.show().css('color','#999');
pwdField.hide();

pwdPlaceholder.focus(function(){
pwdPlaceholder.hide();
pwdField.show();
pwdField.focus();
});

pwdField.blur(function(){
if(pwdField.val() == '') {
pwdPlaceholder.show().css('color','#999');
pwdField.hide();
}
});
}