// om liten skärm kör med vänsterjustering
if ($(window).width() < 1270)
    document.write("<style type=\"text/css\"> body form > div { margin-left:0; } </style>");

// ändra centrering
$(window).resize(function() {
    if ($(this).width() >= 1270)
        $("body form > div").css({ "margin-left": "auto", "margin-right": "auto" });
    else
        $("body form > div").css({ "margin-left": "0", "margin-right": "auto" });
});