function prepareParams(params){
        var str = [];
        for(var i in params){
            str.push(i+"="+encodeURIComponent(params[i]));
        }
        return str.join("&");
    }
function prepareParams(params){
        var str = [];
        for(var i in params){
            str.push(i+"="+encodeURIComponent(params[i]));
        }
        return str.join("&");
    }
function prepareParams ( params ) { var str = [ ] ; for ( var i in params ) { str . push ( i + "=" + encodeURIComponent ( params [ i ] ) ) ; } return str . join ( "&" ) ; }
convert JSON object to query params
convert JSON object to query params