Pdf download via FileReference

programming flash
1

Attempting for the first time to code a pdf download. Here is the code I’m using:

pdfBtn.addEventListener(MouseEvent.CLICK, dothis);

function dothis(e:MouseEvent):void {
		
	var fr:FileReference = new FileReference();
	var req:URLRequest = new URLRequest("this.pdf");
	
	try {
		fr.download(req);
		}
		catch (illegalOperation:IllegalOperationError) {
			// code to handle an illegal operation error
		}
		catch (security:SecurityError) {
			// code to handle a security error
	}
}

Can anyone tell me what I’m doing wrong here? TIA.