function calculatePosition(idOfElement){
        var $element = jQuery(idOfElement);
        var offset = $element.offset();
        var x = offset.left;
        var y = offset.top;
        ....
        ....
    }

var $element = jQuery("#" + idOfElement);

function calculatePosition(idOfElement){
        var $element = jQuery('#' + idOfElement);
        var offset = $element.offset();
        var x = offset.left;
        var y = offset.top;
        ....
        ....
    }