script.js

function getSearchParameters() {
      var prmstr = window.location.search.substr(1);
      return prmstr != null && prmstr != "" ? transformToAssocArray(prmstr) : {};
}

function transformToAssocArray( prmstr ) {
    var params = {};
    var prmarr = prmstr.split("&");
    for ( var i = 0; i < prmarr.length; i++) {
        var tmparr = prmarr[i].split("=");
        params[tmparr[0]] = tmparr[1];
    }
    return params;
}

var params = getSearchParameters();

function searchParam(name, deflt){
    if(Object.keys(params).length == 0){
        return deflt;
    }
    if(params[name]){
        return params[name];
    } else {
        return false;
    }
}