//++++++++++++++++++++返回HttpRequest对象++++++++++++++++++++
function common_GetHttpRequest()
{
  var XmlHR;
  var sBrowser=navigator.appName;

  if (sBrowser=="Microsoft Internet Explorer")//IE
  {
    XmlHR=new ActiveXObject("MSXML2.XMLHTTP");
  }
  else if (sBrowser=="Netscape")//FF
  {
    XmlHR=new XMLHttpRequest();
  }
		else XmlHR=new ActiveXObject("MSXML2.XMLHTTP");//Else

  return XmlHR;
}
//--------------------返回HttpRequest对象--------------------