Email form - please help!

2.swf is my Flash movie which contains a movieclip, where my form fields are for an email form. The following actionscript is applied to the movieclip to take the users to an “Email Sent” screen which is on the next frame:

onClipEvent(data){
// show welcome screen
_root.nextFrame();
}

I have tested this movie and it works fine, the email is sent and the screen moves to the next frame as I want it to.

However it does not go to the next frame when 2.swf is loaded into my main Flash movie, 1.swf, using the .loadMovie AS command. Both files are published as Flash 7 AS2.0. In frame 1 of 2.swf I have placed this line of AS which should have fixed the problem:

this._lockroot = true;

But still, when an email is sent from 2.swf loaded into 1.swf, the next frame is not displayed. Can anyone help me please?