My problem is realy simple. After creating a map by using the following code, the center of the map is not well placed.
var myOptions = {
center: new google.ma
The problem is not in the code you provided. The "top left corner" issue is when the div that contains map doesn't have a size when the map is initialized. You haven't provided the HTML/CSS that specifies the size of the map (or that displays it if it is initially hidden).
Another possibility is that you are initializing the map before DOM is completely rendered, you should be initializing it after the DOM ready or body onload event fires.