var wopened=false;

function visita(){

var WIDTH=620,HEIGHT=450;

var centradox = (screen.width-WIDTH)/2;
var centradoy = (screen.height-HEIGHT)/2;

if (wopened) preview.close()

if (document.layers) {
	preview=eval("window.open('../scripts/visita.php','visita','toolbar=no,location=no,titlebar=no,directories=no,status=no,scrollbars=no,resizable=no,copyhistory=no,width="+(window.screen.availWidth-8)+",height="+(window.screen.availHeight-8)+",screenX=0,screenY=0')");
	wopened=true;
    }
else {
	preview=eval("window.open('../scripts/visita.php','visita','fullscreen=no,toolbar=no,location=no,titlebar=no,directories=no,status=no,scrollbars=no,resizable=no,copyhistory=no,width="+WIDTH+",height="+HEIGHT+",top="+ centradoy +",left=" + centradox + "')");
	wopened=true;
}


}