Read query string with Javascript

function requestQueryString(variable)
{
    var result = null;
    var queryString = window.location.search.substring(1);
    var variables = queryString.split("&");
    for (var i = 0; i < variables.length; i++)
    {
        var pair = variables[i].split("=");
        if (pair[0] == variable)
        {
            result = pair[1];
        }
    }
    return result;
}