Dynamic text box help please

1

hi,
im sort of new to as3
i have created a dynamic text box called noin1

function waterMovement(event:KeyboardEvent):void
{ if(event.keyCode == Keyboard.ENTER){
var waterMove = noin1.text;
trace(waterY);
water.y += waterMove;
}
}

when i call this, to move a movie clip
the trace works and shows the number
but i cannot move the movie clip as flash is not seeing the value ive entered as a number but a string still.

how can i format the text box so that it saves the number inputted as a number or integer.

thanks for any help i get