Question on Update()

Hi,all! I'm trying to make a window that could only be shown when the user both hover the mouse on the object and press the "return" button, but it seems there's something not right. Here is my code:

function OnMouseEnter () {
  MouseSwitch = true;
  print("Entered");
    }

function OnMouseExit () {
  MouseSwitch = false;
}

function Update () {
    if(MouseSwitch && (Input.GetKeyDown(KeyCode.Return))) {
         gameObject.GetComponent(menu).enabled = true;
         SwitchEnabled = true;
    }
}

Can anybody give me a hand? THX!

I change the judge statement a little bit like shown below, this time the code works normally even though I dont know whats the different between this and the one before. And thanks, folks! here is the code:

function Update () {
if( MouseSwitch == true && Input.GetKey("return") ) {
        print("Correct!");
        SwitchEnabled = true;
        gameObject.GetComponent(menu).enabled = true;
}

}

OnMouseEnter() only works with colliders and GUI elements. you should add a collider component to your object.