It is set at 140px in right by default, so set the values for x and y respectively and the box will appear there everytime.
offset values you can arrange yourself.
try this code..
var infowindows = []; //make it global
var popup = new InfoBox({
// size: new google.maps.Size(420,130),
content:content_info
,pixelOffset: new google.maps.Size(10, -100) //these are the offset values to be adjusted accordingly..
,disableAutoPan: false
,closeBoxMargin: "5px 5px 2px 2px"
,boxStyle: {opacity: 0.95
}
});
infowindows.push(popup);
google.maps.event.addListener(marker, 'mouseover', function() {
close_popups();
map.panTo(mycenter1);
popup.open(map, marker);
// currentPopup = null;
});
function close_popups(){
for(var i = 0; i<infowindows.length; i++){
infowindows[i].close();
}
}