function wwOpenWin(url, who, pw, ph)
{
   var decorate=false;
   
   if (pw == null)
       pw=600; 
   else
       if (isNaN(pw) || pw < 100)
       {
           decorate=true;
           pw = screen.availWidth;
       }
       
   if (ph == null)
       ph=500; 
   else
       if (isNaN(ph) || ph < 100)
       {
           decorate=true;
           ph = screen.availHeight;
       }
           
   var tp=(screen.availHeight-ph)/2;
   if (tp<0) tp=0;
   
   var lf=(screen.availWidth-pw)/2;
   if (lf<0) lf=0;
           
   var openArg = 'scrollbars,width='+pw+',height='+ph+',left='+lf+',top='+tp;
   if (decorate) openArg += ',menubar,resizable,status,titlebar,toolbar,directories'; 
   
   var sw = window.open(url, who, openArg);
   
   if (sw.opener == null) sw.opener = window;
   if (navigator.appName == 'Netscape') sw.focus();
   return true;
}