function popupcenter(Url,Name,PosFimX,PosFimY,ScrollBars,Resizable)

{

  PosIniX=((screen.availWidth/2)-(PosFimX/2));

  PosIniY=((screen.availHeight/2)-(PosFimY/2));

  window.open(Url,Name,'toolbar=0,location=0,directories=0,status=1;menubar=0,scrollbars='+ScrollBars+',resizable='+Resizable+',top='+PosIniY+',left='+PosIniX+',width='+PosFimX+',height='+PosFimY+'');

};