JQuery实现简单验证码提示

先看效果图：

要求：当输入框获得焦点时，自动显示验证图片。

代码如下（学习而已，仅供参考）：

/***********************下是验证码对象*****************/
var Validation = {};
Validation.init = function(eleName,imageSrc){
    this.image = imageSrc;
    $(\'#\'+eleName).focusin(function(){
        Validation.show(eleName);
    });
}

Validation.image = \'\';
Validation.display=false;
Validation.width = \'100px\';
Validation.height = \'30px\';
Validation.div = null;
Validation.show = function(eleName){
    if(this.display==false){
        //首次显示
        if(this.div==null){
            $(\'#\'+eleName).after(\'<div style="display:none;" id="div_validation_\'+eleName+\'" title="点击更换"></div>\');
            this.div = $(\'#div_validation_\'+eleName);
            this.div.css(\'position\',\'absolute\');
            this.div.css(\'cursor\',\'pointer\');
            this.div.css(\'border\',\'1px solid #CCC\');
            this.div.css(\'background-color\',\'#FFF\');
            this.div.css(\'background-position\',\'center\');
            this.div.css(\'background-repeat\',\'no-repeat\');
            this.div.css(\'height\',this.height);
            this.div.css(\'width\',this.width);
            var objOffset = $(\'#\'+eleName).offset();
            objOffset.top+=$(\'#\'+eleName).height()+6;
            this.div.offset(objOffset);
            this.div.css(\'background-image\',\'url(\'+Validation.image+\'&_t=\'+new Date()+\')\');
            this.div.css(\'display\',\'inline-block\');
            this.display = true;
            //点击更换
            this.div.click(function(){
                Validation.div.css(\'background-image\',\'url(\'+Validation.image+\'&_t=\'+new Date()+\')\');
            });
        }
        else{
            this.div.css(\'background-image\',\'url(\'+Validation.image+\'&_t=\'+new Date()+\')\');
            this.display = true;
            this.div.css(\'display\',\'inline-block\');
        }
    }
}
Validation.hide =function(){
    if(this.display==true){
        this.display = false;
        this.div.hide();
    }
}

 

使用方式： 

//验证码对象初始化
Validation.init(\'validation\',\'Ajax.ashx?handle=validation\');
//                     输入框ID               验证图片地址    

//隐藏
Validation.hide();