function openModal(link,para,width,height){
	var nWidth,nHeight,nLeft,nTop,sReturn;
	nWidth=width==null?500:width;
	nHeight=height==null?500:height;
	nLeft=(screen.availWidth-nWidth)/2;
	nTop=(screen.availHeight-nHeight)/2;
	
	para += "&tn=";
	para += (new Date()).getTime();
  	sReturn=showModalDialog(root+"/agi/common/frame.jsp?linkUrl="+link+"&"+para ,"","dialogLeft:"+nLeft+"px;dialogTop:"+nTop+"px;dialogHeight:"+nHeight+"px;dialogWidth:"+nWidth+"px");
	return sReturn;
}