Need if-else advice in actionscript3 - string

Question

function clickButtonHandler(event:MouseEvent):void
{
var message:Object = new Object();
message.text = txtMessage.text;
message.userName = txtUser.text;
//Posts to this swf
showMessage(message);
//Posts to ALL OTHER swf files..
group.post(message);
}
function showMessage(message:Object):void
{
output_txt.appendText(message.userName+": "+message.text + "\n");
}
function jsalertwindow(event:MouseEvent):void
{
var alert:URLRequest = new URLRequest("javascript:alert('Please enter your User name')");
navigateToURL(alert, "_self");
}
As you can see there are two function which are contain mouseevent. I want to send those function with an if-else statement. If user write something in text input component which name is txtUser and,
send_btn.addEventListener(MouseEvent.CLICK, clickButtonHandler);
will work, else(if the user forget writing anything)
send_btn.addEventListener(MouseEvent.CLICK, jsalertwindow);
will work.
And one more question should i use MouseEvent.CLICK or MouseEvent.MOUSE_DOWN? Thanks for your advice.

Answer 1

Assign a single handler to the button click (MouseEvent.CLICK is the right event to use) and check the field is populated in the handler:
function clickButtonHandler(event:MouseEvent):void
{
var message:Object = new Object();
// Check the field is populated
if (txtUser.text != "")
{
message.text = txtMessage.text;
message.userName = txtUser.text;
showMessage(message);
//Posts to ALL OTHER swf files..
group.post(message);
}
else
{
// Nothing in the input field, show the alert
showAlert();
}
}
function showMessage(message:Object):void
{
output_txt.appendText(message.userName+": "+message.text + "\n");
}
function showAlert():void
{
var alert:URLRequest = new URLRequest("javascript:alert('Please enter your User name')");
navigateToURL(alert, "_self");
}