$(function(){
	var on = 0,
        maxsize = $(".estate_img ul li").length - 2;
    var blockfun = function() {
        var marginvalue = -(300 + 20) * on;
        $(".estate_block").stop().animate({ marginleft: marginvalue });
    } 
    var nextblock = function() {
        if (on < maxsize) {
            on++;
            blockfun();
        } else {
            on = 0;
            blockfun();
        }
    }  
    var prevblock = function(){
    	if (on > 0) {
            on--;
            blockfun();
        } else {
            on = maxsize;
            blockfun();
        }
    }
    $(".lr_priv").bind("click", function() {
        nextblock();
    })
    $(".lr_next").bind("click", function() {
        prevblock();
    })
})