hide element press Esc

This code doesn't hide the box div which was supposed to be hidden when I press the Esc key.

function Boxup(elementN, event){
    $("#"+elementN).css({
        "display":"block",
        "top":event.pageY+"px" ,
        "left":event.pageX+"px"    
    })
}
function hideCurrentPopup(ele){
    $(ele).parent().hide();
}

    $(this).keyup(function(event) {
        if (event.which == 27) { 
            disablePopup();  
        }   
    });

Am I missing something?