Indy 的post问题

[itcss]

用post方法传送数据，对方没有收到，那个高手能给段代码
我的代码如下：
TStringStream *SourceString = new TStringStream("");
TStringStream *AResponseContentString = new TStringStream("");
AnsiString webaddressstring="http://211.111.111.111:8081/register.php";
PostSourceString="username=aaa&password=bb";

IdHTTP1->Post(webaddressstring,SourceString,AResponseContentString);