$('#upload').on('click',function(){
 $('#upload_form').ajaxForm({
        url:insert_url,
        type:'post',
        target:'#preview',
        beforeSubmit:function(e){
            console.log('before');

            $('.progress').show();
        },
        success:function(res, status, xhr, form){
            console.log('che');
            $('.progress').hide();
        },
        error:function(e){
            console.log('error');

        }
    }).submit();