function Abrir_Ventana(pagina,ancho,alto)
{
	
	var adj=10
	var w = screen.width;
	var h = screen.height;
	var byFactor=1;
	if(w<740){
	  var lift=0.90;
	}
	if(w>=740 & w<835){
	  var lift=0.91;
	}
	if(w>=835){
	  var lift=0.93;
	}
	if (ancho>w){	
	  byFactor = w / ancho;			
	  ancho = w;
	  alto = ancho * byFactor;
	}
	if (alto>h-adj){
	  byFactor = h / alto;
	  ancho = (ancho * byFactor);
	  alto = h; 
	}
	   
	var scrWidth = w-adj;
	var scrHeight = (h*lift)-adj;

	if (alto>scrHeight){
  	  alto=alto*lift;
	  ancho=ancho*lift;
	}

	var posLeft=0;
	var posTop=0;


	var scrHeightTemp = alto - 0;
	if (scrHeightTemp < scrHeight) {
	scrHeight = scrHeightTemp;
	} 
	var scrWidthTemp = ancho - 0;
	if (scrWidthTemp < scrWidth) {
	scrWidth = scrWidthTemp;
	}
	
	if (scrHeight<100){scrHeight=100;}
	if (scrWidth<100){scrWidth=100;}
	
	
	posTop =  ((h-(scrHeight/lift)-adj)/2);
	posLeft = ((w-(scrWidth)-adj)/2);

	if (alto > (h*lift)-adj || ancho > w-adj){
		alto=alto-adj;
		ancho=ancho-adj;
	}
	posTop = parseInt(posTop);
	posLeft = parseInt(posLeft);			
	window.open(pagina,'',CONFIG='HEIGHT='+alto+',WIDTH='+ancho+',TOOLBAR=no,MENUBAR=no,SCROLLBARS=no,RESIZABLE=no,LOCATION=no,DIRECTORIES=no,STATUS=no,left='+posLeft+',top='+posTop)
}

function MostrarImagen(imageName,imageWidth,imageHeight,alt,bgcolor,hugger,hugMargin) {
	if (bgcolor=="") {
		bgcolor="#FFFFFF";
	}
	var adj=10
	var w = screen.width;
	var h = screen.height;
	var byFactor=1;

	if(w<740){
	  var lift=0.90;
	}
	if(w>=740 & w<835){
	  var lift=0.91;
	}
	if(w>=835){
	  var lift=0.93;
	}
	if (imageWidth>w){	
	  byFactor = w / imageWidth;			
	  imageWidth = w;
	  imageHeight = imageHeight * byFactor;
	}
	if (imageHeight>h-adj){
	  byFactor = h / imageHeight;
	  imageWidth = (imageWidth * byFactor);
	  imageHeight = h; 
	}
	   
	var scrWidth = w-adj;
	var scrHeight = (h*lift)-adj;

	if (imageHeight>scrHeight){
  	  imageHeight=imageHeight*lift;
	  imageWidth=imageWidth*lift;
	}

	var posLeft=0;
	var posTop=0;

	if (hugger == "hug image"){
	  if (hugMargin == ""){
	    hugMargin = 0;
	  }
	  var scrHeightTemp = imageHeight - 0 + 2*hugMargin;
	  if (scrHeightTemp < scrHeight) {
		scrHeight = scrHeightTemp;
	  } 
	  var scrWidthTemp = imageWidth - 0 + 2*hugMargin;
	  if (scrWidthTemp < scrWidth) {
		scrWidth = scrWidthTemp;
	  }
	  
	  if (scrHeight<100){scrHeight=100;}
	  if (scrWidth<100){scrWidth=100;}

	  posTop =  ((h-(scrHeight/lift)-adj)/2);
	  posLeft = ((w-(scrWidth)-adj)/2);
 	}

	if (imageHeight > (h*lift)-adj || imageWidth > w-adj){
		imageHeight=imageHeight-adj;
		imageWidth=imageWidth-adj;
	}
	posTop = parseInt(posTop);
	posLeft = parseInt(posLeft);		
	scrWidth = parseInt(scrWidth); 
	scrHeight = parseInt(scrHeight);
	
	var agt=navigator.userAgent.toLowerCase();
	if (agt.indexOf("opera") != -1){
	  var args= new Array();
	  args[0]='parent';
	  args[1]=imageName;
	  var i ; document.MM_returnValue = false;
	  for (i=0; i<(args.length-1); i+=2) eval(args[i]+".location='"+args[i+1]+"'");
	} else {
	newWindow = window.open("scripts/imagen.htm","newWindow","width="+scrWidth+",height="+scrHeight+",left="+posLeft+",top="+posTop);
	newWindow.document.open();
	newWindow.document.write('<html><title>'+alt+'</title><body leftmargin="0" topmargin="0" marginheight="0" marginwidth="0" bgcolor='+bgcolor+' onBlur="self.close()" onClick="self.close()">');  
	newWindow.document.write('<table width='+imageWidth+' border="0" cellspacing="0" cellpadding="0" align="center" height='+scrHeight+' ><tr><td>');
	newWindow.document.write('<img src="'+imageName+'" width='+imageWidth+' height='+imageHeight+' alt="haz click aquí para cerrar" >'); 
	newWindow.document.write('</td></tr></table></body></html>');
	newWindow.document.close();
	newWindow.focus();
	}
}


function validar_fecha(caja){ 
   if (caja){  
      borrar = caja;
      if ((caja.substr(2,1) == "/") && (caja.substr(5,1) == "/")){      
         for (i=0; i<10; i++){	
            if (((caja.substr(i,1)<"0") || (caja.substr(i,1)>"9")) && (i != 2) && (i != 5)){
               borrar = '';
               break;  
			}  
         }
	     if (borrar){ 
	        a = caja.substr(6,4);
		    m = caja.substr(3,2);
		    d = caja.substr(0,2);
		    if((a < 1900) || (a > 2050) || (m < 1) || (m > 12) || (d < 1) || (d > 31))
		       borrar = '';
		    else{
		       if((a%4 != 0) && (m == 2) && (d > 28))	   
		          borrar = '';
			   else{
		          if ((((m == 4) || (m == 6) || (m == 9) || (m==11)) && (d>30)) || ((m==2) && (d>29)))
			         borrar = '';	      				  	 
			   }
		    }
         }
      }
	  else
	     borrar = '';
	  if (borrar == '')
	     alert('Debe Introducir una fecha con este formato "dd/mm/yyyy"');
   }
}