$(document).ready(function(){

    $('.arrow_right').click(function(){
        
        var innerdiv = $('.gallery_in');
        
        var left = innerdiv[0].style.left || 0;
        
         if (parseInt(left) > 140*3-parseInt(innerdiv[0].style.width)) {
        innerdiv.animate({left: '-=140'});
         }
    })
          
    $('.arrow_left').click(function(){
        
        var innerdiv = $('.gallery_in');
        
        var left = innerdiv[0].style.left || 0; 
         if (parseInt(left) < 0) {
        innerdiv.animate({left: '+=140'});
         }
    })
   
});