Tooltip changes places

JavaScript
1

Hi,
I am using a tooltip that uses the following javascript

<script type="text/javascript">
$(document).ready(function() {
    //Tooltips
    $(".tip_trigger").hover(function(){
        tip = $(this).find('.tip');
        tip.show(); //Show tooltip
    }, function() {
        tip.hide(); //Hide tooltip
    }).mousemove(function(e) {
        var mousex = e.pageX - 90; //Get X coodrinates
        var mousey = e.pageY  - 400; //Get Y coordinates
        var tipWidth = tip.width(); //Find width of tooltip
        var tipHeight = tip.height(); //Find height of tooltip

        //Distance of element from the right edge of viewport
        var tipVisX = $(window).width() - (mousex + tipWidth);
        //Distance of element from the bottom of viewport
        var tipVisY = $(window).height() - (mousey + tipHeight);

        if ( tipVisX < 90 ) { //If tooltip exceeds the X coordinate of viewport
            mousex = e.pageX - tipWidth - 90;
        } if ( tipVisY < 90 ) { //If tooltip exceeds the Y coordinate of viewport
            mousey = e.pageY - tipHeight - 90;
        }
        //Absolute position the tooltip according to mouse position
        tip.css({  top: mousey, left: mousex });
    });
});
</script>

As you can see I have set its X position at -90 and y position at -400 so that It could be displaying well when the mouse is hover over a link and it do appear well in the testing page http://bloghutsbeta.blogspot.com/2012/04/testing-slidernav.html
If you put your mouse over ALEX in ‘A’ category BUT from the same test site but in different location from above here http://bloghutsbeta.blogspot.com/2012/04/testing-main.html if you put your mouse over ALEX under ‘SIMULATION’ category then you will see that the tooltip is way down.

Not even that the tooltip moves away if the screen resolution changes. I changed value again and again but didn’t reach any conclusion, can someone help me with this issue as what to do to fix it?

Note: If you require a complete markup please let me know in comment, I considered it not required that’s why I didn’t added it to my post ^^