Walk test

hey i am making a character that walks in the swf the code for walking is

onClipEvent (load)
{
setProperty("", _x, 0);
setProperty("", _y, 0);
speed = 5;
}

onClipEvent (mouseDown)
{
endX = _root._xmouse;
endY = _root._ymouse;
}

onClipEvent (enterFrame)
{
setProperty("", _x, _x + (endX - _x) / speed);
setProperty("", _y, _y + (endY - _y) / speed);
}

well that code works good
i am making another moviclip named blocker i want my character cant walk in the walker anybody know the code?