// javascript document
(function($) {

    jquery.fn.imgfloat = function(options) {
        var own = this;
        var xd = 0;
        var yd = 0;
        var i = 1;
        var settings = {
            speed: 20,
            xpos: 0,
            ypos: 1
        };
        jquery.extend(settings, options);
        var owntop = settings.xpos;
        var ownleft = settings.ypos;
        own.css({
            position: "fixed",
            
        });
        function imgposition() {
            var winwidth = $(window).width() - own.width();
            var winheight = $(window).height() - own.height();
            //控制横向运动轨迹
			if (xd == 0) {
                ownleft += i;
                own.css({
                    left: ownleft
                });
                if (ownleft >= winwidth) {
                    ownleft = winwidth;
                    xd = 1;
                }
            }
            if (xd == 1) {
                ownleft -= i;
                own.css({
                    left: ownleft
                });
                if (ownleft <= 0) xd = 0;
            }
			//控制纵向运动轨迹
            if (yd == 0) {
                owntop += i;
                own.css({
                    top: owntop
                });
                if (owntop >= winheight) {
                    owntop = winheight;
                    yd = 1;
                }
            }
            if (yd == 1) {
                owntop -= i;
                own.css({
                    top: owntop
                });
                if (owntop <= 0) yd = 0;
            }
        }
        var imghover = setinterval(imgposition, settings.speed);
        own.hover(function() {
            clearinterval(imghover);
        },
        function() {
            imghover = setinterval(imgposition, settings.speed);
        });
    }
})(jquery);