Error calling javascript function using

I’m attempting to execute Javascript code (the fromFlash() function) that’s in an .HTM file, in which is embedded my .SWF file. I’m using the following code in the .FLA file:

myButton.addEventListener(MouseEvent.CLICK, runExp);
function runExp(e:MouseEvent):void {"fromFlash");

When, from the .HTM file, I click myButton, I get the following error:

SecurityError: Error #2060: Security sandbox violation: ExternalInterface caller [file:///C:/_Flash/email/email.swf cannot access file:///C:/_Flash/email/loadFlash.htm](file:///C:/_Flash_learning/email/email.swf).

Any insights?