web前端技术--Placeholder

1.

var funPlaceholder = function(element) {
     var placeholder = '';
     if (element && !("placeholder" in document.createElement("input"))
       && (placeholder = element.getAttribute("placeholder"))) {
      element.onfocus = function() {
           if (this.value === placeholder) {
            this.value = "";
           }
       this.style.color = '#000';
      };
      element.onblur = function() {
       if (this.value === "") {
        this.value = placeholder;
        this.style.color = '#999';
   } else {
    this.style.color = '#000';
   }
  };

  // 样式初始化
  if (element.value === "") {
   element.value = placeholder;
   element.style.color = '#999';
  }
 }
};

2.

 var  IePlaceholder=function(){
        var doc = window.document, input = doc.createElement('input');
        if( typeof input['placeholder'] == 'undefined' ) // 如果不支持placeholder属性
        {
            $('input').each(function( ele )
            {
                var me = $(this);
                var ph = me.attr('placeholder');
                if( ph && !me.val() )
                {
                    me.val(ph).css('color', '#aaa').css('line-height', me.css('height'));
                }
                me.on('focus', function()
                {
                    if( me.val() === ph)
                    {
                        me.val(null).css('color', '');
                    }
                }).on('blur', function()
                        {
                            if( !me.val() )
                            {
                                me.val(ph).css('color', '#aaa').css('line-height', me.css('height'));
                            }
                        });
            });
        }
    }