function AbrirVentana(URL,NOMBRE,ANCHO,ALTO,scrollbars)
{
	var xposition = 200; 
	var yposition = 150;
	
	if ((parseInt(navigator.appVersion) >= 4 ))
		{
		xposition = (screen.width -ANCHO) / 2;
		yposition = (screen.height - ALTO) / 2;
		 }
	
	if (!scrollbars) var scrollbars = 0;

	var args = "width=" + ANCHO + ","
		+ "height=" + ALTO + ","
		+ "location=0,"
		+ "menubar=0,"
		+ "scrollbars=" + scrollbars + ","
		+ "status=0,"
		+ "titlebar=0,"
		+ "hotkeys=0,"
		+ "screenx=" + xposition + ","		// NN Only
		+ "screeny=" + yposition + ","		// NN Only
		+ "left=" + xposition + ","		// IE Only
		+ "top=" + yposition;		// IE Only
		
	window.open(URL,NOMBRE,args);
}