Hi I got it sorted, needed to declare onClickedSend event as below, for anyone who cares!

//send script:

var mLocalConnection:LocalConnection;
mLocalConnection=new LocalConnection();
mLocalConnection.addEventListener(StatusEvent.STAT US, onLocalConnectionStatus);

sendButton.addEventListener(MouseEvent.CLICK, onClickedSend);

function onClickedSend(e:Event):void
{
mLocalConnection.send("myLocalConnection", "streamHandler");
}

function onLocalConnectionStatus(statusEvent:StatusEvent):v oid
{
if (statusEvent.level=="error")
{
trace(statusEvent.code);
}
}

//receive script:

var mLocalConnection:LocalConnection;
mLocalConnection=new LocalConnection();
mLocalConnection.connect("myLocalConnection");
mLocalConnection.client=this;
mLocalConnection.addEventListener(StatusEvent.STAT US, onLocalConnectionStatus);


function onLocalConnectionStatus(statusEvent:StatusEvent):v oid
{
if (statusEvent.level=="error")
{
}
}

function streamHandler():void {

// stops publishing the stream
nsStream.pause();

// deletes the source stream connection
ncConnection.close();


}