给一个控件添加内容

 function getman()
   {
        var ss=document.getElementById("lstRName");
        var aa=document.getElementById("txtReportMan");
        for(var i=0;i <ss.length;i++) {
            if (ss.options[i].selected) {
                var s1=ss.options[i].value;
                if(aa.value=='')
                {
                    aa.value=s1;
                }
                else
                {
                    aa.value=aa.value+' '+s1;
                }
            }
        }