Ignore script if there is no selection?

[rcraighead]

How do I write this so AI does not show error messages if nothing is selected?

var aDoc = app.activeDocument;
app.userInteractionLevel.DONTDISPLAYALERTS
var myLayer = "";
//Unite BACK TEXT selection
selection = null;
try {
  (aDoc.layers.getByName("BACK TEXT"));
  var myLayer = aDoc.layers.getByName("BACK TEXT");
  myLayer.hasSelectedArtwork = true;
  app.executeMenuCommand("outline");//AI message: "Can't create type outlines."
  app.doScript("Unite", "AI Actions_KM");//AI message: "The filter produced no results."
} catch (e) {
  //alert here
}
selection = null;

I tried: "app.userInteractionLevel.DONTDISPLAYALERTS" but it had no effect.

Thanks.

[pixxxelschubser · Accepted solution]

Sended from phone

if ( app.selection.length > 0 ) {

    alert ("selected");

    }

else {

    alert ("nothing is selected");

    }

Have fun