you can try this and this will work
$(document).ready(function(e) {
var len = $('.slider_mian_cont ul li').length;
var wd = $('.slider_mian_cont ul').width();
var mn=len*wd;
//var mn = $('.slider_inner').width(wd*len);
var testa = $('.slider_mian_cont ul li').width();
//console.log(len, wd);
//console.log(mn);
$('#next').click(function(){
var leftValue = $('.slider_inner').position().left;
//console.log(leftValue);
var movedValue = leftValue - testa;
var posv=Math.abs(leftValue)
var mix= posv+testa+wd;
console.log(mix , mn);
//$(this).toggle(mn <= mix)
if(mix == mn){ $('#next').toggle();}
$('.slider_inner').animate({ left: movedValue }, 200 )
});
});