function build_flashquerystring(obj){if(typeof obj!=='object'){return null;}
var list=[];for(var k in obj){k=encodeURIComponent(k);var value=obj[k];if(obj[k]instanceof Array){for(var i in value){list.push(k+'[]='+encodeURIComponent(value[i]));}}else{list.push(k+'='+encodeURIComponent(value));}}
return list.join('&');}