when i move one of four draggables, and right click on it -to make another DIV appear- ALL the rest elements move down

when i move one of four draggables, and right click on it -to make another DIV appear- ALL the rest elements move down

part of code here:

//**********************************************************************************
$('#mymenu').hide();
$('#mymenu, #mytop, #myleft, #myright, #mybottom').resizable();
$('#mymenu, #mytop, #myleft, #myright, #mybottom').draggable();
//**********************************************************************************

$('#mytop').mousedown(function(event) {

whichElement = "#mytop";
    if(event.which == 3) {
$('#mymenu').animate({'left': + event.pageX + 'px'}, 1);
$('#mymenu').animate({'top': + event.pageY + 'px'}, 1);
$('#mymenu').show();

$('#mymenu').css('z-index','123');

$('#myp').mousedown(function(event) {
$('#mymenu').hide();
return false;
});

}
});

//*********************************************************************************