function broadcastmessage(sheet_id) {

//	generate message to all helpers on this sign up sheet

	//get user inputs
	var user_message = document.getElementById("message").value;
	
	// Build the URL to connect to
	createRequest();
	var url = "generatemessage.php";

	// Open a connection to the server
	request.open("POST", url, true);

	// Setup a function for the server to run when it's done
	request.onreadystatechange = confirmmessage;
	request.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

	// Build and send the request
	var post_data = "sheet_id=" + escape(sheet_id);
	post_data = post_data + "&message=" + escape(user_message);
	
	request.send(post_data);	
}