function abrir()
{window.open ('fechas.html' ,'', 'scrollbars=yes,menubars=no,toolbars=no,resizable=no,height=400,width=500' , '');
}
function selectWin(source,h1,w1)
{ newWin = window.open(source,'','height=' + h1 + ',width=' + w1 + ',top=100,left=100, scrollbars=yes');
}

function PopUp(img, ancho, alto)
{
derecha=(screen.width-ancho)/0;
arriba=(screen.height-alto)/0;
string="toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=yes,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
fin=window.open(img,"",string);
}

function PopUpBl(img, ancho, alto)
{
derecha=(screen.width-ancho)/0;
arriba=(screen.height-alto)/0;
string="toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=no,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
fin=window.open(img,"",string);
}

<!--
function CargarFoto(img, ancho, alto){
derecha=(screen.width-ancho)/0;
arriba=(screen.height-alto)/0;
string="toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,resizable=yes,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
fin=window.open(img,"",string);
}
// -->

<!-- OTROS  // -->
function CaricaFoto(img){
  foto1= new Image();
  foto1.src=(img);
  Controlla(img);
}
function Controlla(img){
  if((foto1.width!=0)&&(foto1.height!=0)){
    viewFoto(img);
  }
  else{
    funzione="Controlla('"+img+"')";
    intervallo=setTimeout(funzione,20);
  }
}
function viewFoto(img){
  largh=foto1.width+20;
  altez=foto1.height+20;
  stringa="width="+largh+",height="+altez;
  finestra=window.open(img,"",stringa);
}

function cerrarse(){
window.close()
}