Get UTM parameter values and run script

Run script based on UTM parameters

    // Get all URL parameters
    function getUrlParameter(sParam)
    {
        var sPageURL = window.location.search.substring(1);
        var sURLVariables = sPageURL.split('&');
        for (var i = 0; i < sURLVariables.length; i++)
        {
            var sParameterName = sURLVariables[i].split('=');
            if (sParameterName[0] == sParam)
            {
                return sParameterName[1];
            }
        }
    }
    // Set utm_campaign
    var utm_campaign = getUrlParameter($param);
        if (utm_campaign) {
            // some code
        }