Problems with a tellTarget

i don’t know why this isn’t working.

i got a button. and when it’s pressed, i need it to go and play a frame in a movie clip.

i’ll test it and then when i click on it, i get this:

Target not found: Target=“whoweare” Base="_level0.instance20.instance48.instance49"

this is the code that i am using:

on (press) {
tellTarget (“whoweare”) {
gotoAndPlay (51);
}
}

am i just stupid???